` element included in the response body alongside the card HTML.
+
+The edit flow uses `outerHTML` swaps on named zone elements (`.tablo-title-zone`, `.tablo-desc-zone`, `.tablo-delete-zone`) so each fragment completely replaces its host element on every round-trip. This is the established Phase 2 fragment pattern (form re-renders with errors via `outerHTML` swap).
+
+For the `updated_at` column, explicit `SET updated_at = now()` in the sqlc UPDATE query is preferred over a Postgres trigger — it keeps logic in the query layer where sqlc can see it, avoids migration-time trigger creation boilerplate, and matches the Phase 2 convention (users table sets `updated_at` explicitly where needed).
+
+**Primary recommendation:** Follow the Phase 2 handler constructor pattern (`TablosDeps` struct, handlers return `http.HandlerFunc`), add `/tablos*` routes inside the existing `RequireAuth` chi group, and use `hx-swap-oob` for the dual-target create success response.
+
+---
+
+## Architectural Responsibility Map
+
+| Capability | Primary Tier | Secondary Tier | Rationale |
+|------------|-------------|----------------|-----------|
+| Tablo list (dashboard) | Go server (templ render) | — | Full page + DB query at request time |
+| Create form expand | Go server (HTMX fragment) | — | Server renders the inline form HTML |
+| Create mutation | Go server (handler) | Postgres | Validation, insert, fragment response |
+| Detail page render | Go server (templ) | Postgres | DB fetch + ownership check |
+| Inline edit fragments | Go server (HTMX fragment) | — | Server renders editable inputs |
+| Edit mutation | Go server (handler) | Postgres | Validation, update, fragment response |
+| Delete confirmation | Go server (HTMX fragment) | — | Server renders confirm row |
+| Delete mutation | Go server (handler) | Postgres | Hard delete, card removal from DOM |
+| CSRF protection | Go server (gorilla/csrf) | — | Locked middleware from Phase 2 |
+| Auth gating | Go server (RequireAuth middleware) | — | Locked from Phase 2 |
+| Ownership enforcement | Go server (handler logic) | — | `auth.Authed(ctx)` + DB row check → 404 |
+
+---
+
+## Standard Stack
+
+### Core (all verified in go.mod / existing codebase)
+
+| Library | Version | Purpose | Why Standard |
+|---------|---------|---------|--------------|
+| `github.com/go-chi/chi/v5` | v5.2.5 | Router, URL params (`chi.URLParam`) | Locked Phase 1 |
+| `github.com/a-h/templ` | v0.3.1020 | HTML template compilation | Locked Phase 1 |
+| `github.com/jackc/pgx/v5` | v5.9.2 | Postgres driver + `pgtype` nullable types | Locked Phase 1 |
+| `github.com/pressly/goose/v3` | v3.27.1 | Migration runner | Locked Phase 1 |
+| `github.com/gorilla/csrf` | v1.7.3 | CSRF token validation | Locked Phase 2 |
+| `github.com/google/uuid` | v1.6.0 | UUID parsing from URL path params | Locked Phase 1 |
+| sqlc v1.31.1 | (CLI tool) | Generate type-safe Go from SQL | Locked Phase 1 |
+
+[VERIFIED: backend/go.mod and justfile]
+
+### Nullable Column Handling with sqlc + pgx/v5
+
+`description text` and `color text` are nullable. sqlc with `pgx/v5` generates `pgtype.Text` for nullable `text` columns. The template receives the Go struct field and must check `.Valid` before rendering.
+
+```go
+// Generated model shape for nullable text:
+type Tablo struct {
+ ID uuid.UUID
+ UserID uuid.UUID
+ Title string
+ Description pgtype.Text // .Valid = true when non-null, .String = value
+ Color pgtype.Text
+ CreatedAt pgtype.Timestamptz
+ UpdatedAt pgtype.Timestamptz
+}
+```
+
+[VERIFIED: backend/internal/db/sqlc/models.go — User.CreatedAt uses pgtype.Timestamptz; same pattern applies to text nullables]
+
+---
+
+## Architecture Patterns
+
+### System Architecture Diagram
+
+```
+Browser
+ │
+ │ GET / (full page)
+ │ GET /tablos/new (HTMX fragment)
+ │ POST /tablos (HTMX fragment or 303)
+ │ GET /tablos/{id} (full page)
+ │ GET /tablos/{id}/edit-title (HTMX fragment)
+ │ POST /tablos/{id} (HTMX fragment or 303)
+ │ GET /tablos/{id}/show-title (HTMX fragment — cancel)
+ │ GET /tablos/{id}/delete-confirm (HTMX fragment)
+ │ POST /tablos/{id}/delete (200+HX-Redirect or 303)
+ │ GET /tablos/{id}/delete-cancel (HTMX fragment)
+ ▼
+chi Router ──► RequireAuth middleware ──► auth.Authed(ctx) → *auth.User
+ │
+ ├─► TablosListHandler → sqlc.ListTablosByUser → templ.TablosDashboard (full) or TablosListFragment (HTMX)
+ ├─► TablosNewHandler → templ.TabloCreateFormFragment
+ ├─► TablosCreateHandler → validate → sqlc.InsertTablo → card fragment + OOB clear form slot
+ ├─► TabloDetailHandler → sqlc.GetTabloByID → ownership check → templ.TabloDetailPage
+ ├─► TabloEditTitleHandler → templ.TabloTitleEditFragment
+ ├─► TabloUpdateHandler → validate → sqlc.UpdateTablo → templ.TabloTitleDisplay / TabloDescDisplay
+ ├─► TabloShowTitleHandler → templ.TabloTitleDisplay (cancel edit)
+ ├─► TabloDeleteConfirmHandler → templ.TabloDeleteConfirmFragment
+ ├─► TabloDeleteHandler → sqlc.DeleteTablo → 200+HX-Redirect:/ or 303:/
+ └─► TabloDeleteCancelHandler → templ.TabloDeleteButtonFragment
+ │
+ ▼
+ Postgres (tablos table)
+```
+
+### Recommended Project Structure
+
+```
+backend/
+├── internal/
+│ ├── tablos/ # Phase 1 placeholder (doc.go only) — fill in Phase 3
+│ │ └── doc.go # keep package declaration, implementation in web layer
+│ ├── db/
+│ │ ├── queries/
+│ │ │ └── tablos.sql # NEW — sqlc source queries
+│ │ └── sqlc/
+│ │ ├── tablos.sql.go # generated by sqlc generate
+│ │ └── models.go # updated with Tablo struct
+│ └── web/
+│ ├── handlers_tablos.go # NEW — TablosDeps + all tablo handlers
+│ └── router.go # MODIFIED — add /tablos* routes
+├── migrations/
+│ └── 0003_tablos.sql # NEW — tablos table + index
+└── templates/
+ └── tablos.templ # NEW — all tablo templates
+```
+
+Note: `internal/tablos/` remains a thin package (Phase 1 placeholder shell). All tablo handler logic lives in `internal/web/handlers_tablos.go` following the AuthDeps / handlers_auth.go precedent. There is no separate service layer in this codebase.
+
+### Pattern 1: Handler Constructor with Deps Struct
+
+Every handler group follows the `AuthDeps` pattern exactly — a struct holding dependencies, handler functions as closures returned from constructors.
+
+```go
+// Source: backend/internal/web/handlers_auth.go (established pattern)
+
+// TablosDeps holds dependencies for all tablo handlers.
+type TablosDeps struct {
+ Queries *sqlc.Queries
+}
+
+// TablosListHandler renders GET / — the dashboard with the user's tablos.
+func TablosListHandler(deps TablosDeps) http.HandlerFunc {
+ return func(w http.ResponseWriter, r *http.Request) {
+ _, user, _ := auth.Authed(r.Context())
+ tablos, err := deps.Queries.ListTablosByUser(r.Context(), user.ID)
+ if err != nil {
+ http.Error(w, "internal server error", http.StatusInternalServerError)
+ return
+ }
+ w.Header().Set("Content-Type", "text/html; charset=utf-8")
+ _ = templates.TablosDashboard(user, csrf.Token(r), tablos).Render(r.Context(), w)
+ }
+}
+```
+
+[VERIFIED: backend/internal/web/handlers_auth.go — AuthDeps pattern]
+
+### Pattern 2: HTMX Request Detection
+
+Check `r.Header.Get("HX-Request") == "true"` to branch between fragment and full-page response. Established in Phase 2 and used throughout.
+
+```go
+// Source: backend/internal/web/handlers_auth.go — renderSignupError
+if r.Header.Get("HX-Request") == "true" {
+ _ = templates.TabloCreateFormFragment(form, errs, csrf.Token(r)).Render(r.Context(), w)
+} else {
+ _ = templates.TablosDashboard(user, csrf.Token(r), tablos).Render(r.Context(), w)
+}
+```
+
+[VERIFIED: backend/internal/web/handlers_auth.go]
+
+### Pattern 3: HTMX-Aware Redirect
+
+For post-delete navigation back to `/`:
+
+```go
+// Source: backend/internal/web/handlers_auth.go (logout/signup patterns)
+if r.Header.Get("HX-Request") == "true" {
+ w.Header().Set("HX-Redirect", "/")
+ w.WriteHeader(http.StatusOK)
+ return
+}
+http.Redirect(w, r, "/", http.StatusSeeOther)
+```
+
+[VERIFIED: backend/internal/web/handlers_auth.go — LogoutHandler, SignupPostHandler]
+
+### Pattern 4: Dual-Target Swap on Create Success
+
+HTMX v2's `hx-swap-oob` (out-of-band swap) lets a single response update two DOM regions. On successful create, the handler returns HTML containing:
+1. The new tablo card (primary body — swapped into `#create-form-slot` per the form's `hx-target`)
+2. An empty `
` to clear the form
+
+Wait — this is backwards. The form's `hx-post` targets `#create-form-slot`. To prepend to `#tablos-list`, use `HX-Retarget` + `HX-Reswap` headers to change where the primary response lands, AND include an out-of-band element to clear the form slot.
+
+```go
+// Successful create handler response:
+w.Header().Set("Content-Type", "text/html; charset=utf-8")
+w.Header().Set("HX-Retarget", "#tablos-list")
+w.Header().Set("HX-Reswap", "afterbegin")
+// Body: card HTML + OOB empty div to clear form slot
+_ = templates.TabloCardWithOOBFormClear(tablo, csrfToken).Render(r.Context(), w)
+```
+
+The template includes both the card and the out-of-band form-clear element:
+
+```templ
+// TabloCardWithOOBFormClear renders a card plus an OOB element to clear #create-form-slot.
+templ TabloCardWithOOBFormClear(tablo sqlc.Tablo, csrfToken string) {
+ @TabloCard(tablo, csrfToken)
+
+}
+```
+
+[VERIFIED: HTMX docs — HX-Retarget, HX-Reswap, hx-swap-oob are all valid HTMX v2 response headers/attributes]
+
+### Pattern 5: Ownership Check → 404
+
+```go
+// In TabloDetailHandler and any handler that fetches a specific tablo:
+tablo, err := deps.Queries.GetTabloByID(r.Context(), tabloID)
+if err != nil {
+ if errors.Is(err, pgx.ErrNoRows) {
+ http.NotFound(w, r)
+ return
+ }
+ http.Error(w, "internal server error", http.StatusInternalServerError)
+ return
+}
+// D-04: 404 for non-owner, not 403 — no information leakage
+if tablo.UserID != user.ID {
+ http.NotFound(w, r)
+ return
+}
+```
+
+[VERIFIED: CONTEXT.md D-04]
+
+### Pattern 6: UUID Extraction from URL Params
+
+```go
+// chi URL parameter extraction + uuid parsing
+import (
+ "github.com/go-chi/chi/v5"
+ "github.com/google/uuid"
+)
+
+idStr := chi.URLParam(r, "id")
+tabloID, err := uuid.Parse(idStr)
+if err != nil {
+ http.NotFound(w, r)
+ return
+}
+```
+
+[VERIFIED: backend/go.mod — chi v5.2.5, uuid v1.6.0]
+
+### Pattern 7: Router Extension — Tablos Route Group
+
+```go
+// In NewRouter (router.go), inside the RequireAuth group:
+r.Group(func(r chi.Router) {
+ r.Use(auth.RequireAuth)
+ r.Get("/", TablosListHandler(tabloDeps)) // replaces IndexHandler
+ r.Post("/logout", LogoutHandler(deps))
+ // New tablo routes:
+ r.Get("/tablos/new", TablosNewHandler(tabloDeps))
+ r.Post("/tablos", TablosCreateHandler(tabloDeps))
+ r.Get("/tablos/{id}", TabloDetailHandler(tabloDeps))
+ r.Post("/tablos/{id}", TabloUpdateHandler(tabloDeps))
+ r.Get("/tablos/{id}/edit-title", TabloEditTitleHandler(tabloDeps))
+ r.Get("/tablos/{id}/show-title", TabloShowTitleHandler(tabloDeps))
+ r.Get("/tablos/{id}/edit-desc", TabloEditDescHandler(tabloDeps))
+ r.Get("/tablos/{id}/show-desc", TabloShowDescHandler(tabloDeps))
+ r.Get("/tablos/{id}/delete-confirm", TabloDeleteConfirmHandler(tabloDeps))
+ r.Get("/tablos/{id}/delete-cancel", TabloDeleteCancelHandler(tabloDeps))
+ r.Post("/tablos/{id}/delete", TabloDeleteHandler(tabloDeps))
+})
+```
+
+Note: chi routes are matched in declaration order. `GET /tablos/new` must be declared before `GET /tablos/{id}` or chi will try to parse "new" as a UUID ID. chi v5 handles this correctly when static segments precede parametric ones if declared first — but explicit ordering is safest.
+
+[VERIFIED: chi v5 routing behavior — static routes take precedence over parametric routes at the same depth]
+
+### Pattern 8: Non-HTMX Form Fallback
+
+Every mutating form includes `method="POST"` + `action="/tablos"` so it works without JS. The handler checks `HX-Request` and falls back to `303` redirect:
+
+```go
+// Non-HTMX create success:
+http.Redirect(w, r, "/", http.StatusSeeOther)
+```
+
+[VERIFIED: backend/internal/web/handlers_auth.go — established pattern throughout]
+
+### Anti-Patterns to Avoid
+
+- **`hx-delete` on forms:** HTML forms only support GET/POST. Use `POST /tablos/{id}/delete` for delete (non-HTMX compatible). HTMX can use `hx-post="/tablos/{id}/delete"` or `hx-delete` (HTMX will send DELETE via XHR, but the non-HTMX fallback form must use POST). Per UI-SPEC interaction contract, use `hx-post="/tablos/{id}/delete"` to keep a working non-HTMX fallback.
+- **`r.Body` instead of `r.PostFormValue`:** gorilla/csrf consumes the body. Always use `r.PostFormValue()` (established in Phase 2, comment: "Pitfall 1").
+- **Static route after parametric route:** Declaring `GET /tablos/{id}` before `GET /tablos/new` causes "new" to be interpreted as a UUID ID and fail parsing.
+- **CSS nesting in ui/*.css:** Established prohibition — no `&:hover` nesting, all selectors top-level (confirmed in button.css comment).
+- **CDN HTMX:** Script served from `/static/htmx.min.js`, never CDN (layout.templ locked pattern).
+
+---
+
+## Don't Hand-Roll
+
+| Problem | Don't Build | Use Instead | Why |
+|---------|-------------|-------------|-----|
+| CSRF token injection | Custom hidden field logic | `@ui.CSRFField(csrfToken)` | Already in Phase 2 |
+| UUID generation for PKs | Custom ID generation | `DEFAULT gen_random_uuid()` in SQL | Postgres built-in, Phase 2 pattern |
+| UUID parsing from URL | Manual string parsing | `uuid.Parse(chi.URLParam(r, "id"))` | Type-safe, handles malformed input |
+| Nullable text rendering | Manual nil check | `pgtype.Text{Valid, String}` struct | sqlc generates this automatically |
+| Auth checking | Custom session lookup in handlers | `auth.Authed(r.Context())` | Middleware already resolved session |
+| HTMX-aware redirects | Ad-hoc header setting | The `redirectTo` pattern in `auth.middleware.go` | Established helper (could extract) |
+| Form error rendering | Custom error HTML | `@templates.FieldError(msg)` + `@templates.GeneralError(msg)` | Phase 2 established components |
+| Button danger/neutral CSS | Inline styles | `ui-button-solid-danger-md` + `ui-button-soft-neutral-md` CSS classes | New but specified in UI-SPEC |
+
+**Key insight:** This phase reuses nearly all established infrastructure. The only net-new code is the DB migration, sqlc queries, tablo handler file, and tablo templ file.
+
+---
+
+## Common Pitfalls
+
+### Pitfall 1: `/tablos/new` Parsed as a UUID ID
+
+**What goes wrong:** `GET /tablos/new` matches `GET /tablos/{id}` if the parametric route is registered first. chi tries `uuid.Parse("new")` → fails → 404 or panic.
+
+**Why it happens:** chi matches parametric routes eagerly unless a static route is declared first.
+
+**How to avoid:** Register `r.Get("/tablos/new", ...)` before `r.Get("/tablos/{id}", ...)` in the route group.
+
+**Warning signs:** `GET /tablos/new` returns 404 or a UUID parse error log.
+
+### Pitfall 2: `r.Body` vs `r.PostFormValue` with gorilla/csrf
+
+**What goes wrong:** gorilla/csrf reads `r.Body` to extract the `_csrf` field. If the handler calls `r.Body.Read()` or `io.ReadAll(r.Body)` before CSRF validation, the body is drained, CSRF token is missing, and the request is rejected with 403.
+
+**Why it happens:** gorilla/csrf operates as middleware before handler — but if the handler reads the body first in a different middleware, the body is gone.
+
+**How to avoid:** Always use `r.PostFormValue("field")` — it calls `r.ParseForm()` which caches the parsed form, so repeated reads are safe.
+
+**Warning signs:** 403 CSRF failures on POST requests that include the hidden `_csrf` field.
+
+### Pitfall 3: Missing `templ generate` After Editing `.templ` Files
+
+**What goes wrong:** Go compiler sees the old `*_templ.go` generated file. New template functions/components don't exist, causing "undefined" compile errors.
+
+**Why it happens:** `templ generate` is a code generation step that must run before `go build`/`go test`. `just generate` or `just dev` runs it, but manual `go test` doesn't.
+
+**How to avoid:** Run `just generate` (or `just dev`) before any Go compile step. The `just test` recipe runs `just generate` first.
+
+**Warning signs:** `undefined: templates.TablosDashboard` compile error even though the `.templ` file exists.
+
+### Pitfall 4: Tailwind Class Discovery for New CSS Files
+
+**What goes wrong:** New CSS classes in `backend/internal/web/ui/button.css` (the danger/neutral variants) are not emitted in `static/tailwind.css` because Tailwind's `@source` scanning only covers `.templ` and `.go` files, not `.css` files referenced via `@import`.
+
+**Why it happens:** `tailwind.input.css` uses `@import "./internal/web/ui/button.css"` — these static CSS rules are included by PostCSS/Tailwind as-is. The new `.ui-button-solid-danger-md` rules ARE included because they are in the imported file, not because Tailwind scans class names. This is actually fine — imported CSS files pass through verbatim.
+
+**How to avoid:** Add new button variant CSS rules to `backend/internal/web/ui/button.css` directly. They will be included in the output via the `@import`. Re-run `just generate` (which rebuilds Tailwind) after modifying the CSS.
+
+**Warning signs:** Buttons render unstyled. Check that `just generate` was run and `static/tailwind.css` contains the new class rules.
+
+### Pitfall 5: hx-swap-oob Element Must Be Top-Level in Response Body
+
+**What goes wrong:** An out-of-band `
` nested inside another element is not processed by HTMX as OOB — it must be a direct sibling at the top level of the response body.
+
+**Why it happens:** HTMX processes OOB elements by scanning the top-level children of the response fragment.
+
+**How to avoid:** The `TabloCardWithOOBFormClear` template must render the card and the OOB div as siblings (both children of an implicit fragment, not wrapped in a container).
+
+**Warning signs:** `#create-form-slot` still shows the old form after successful create.
+
+### Pitfall 6: `pgtype.Text` Null Check in Templates
+
+**What goes wrong:** Passing `tablo.Description.String` to a template when `tablo.Description.Valid` is false renders an empty string — usually harmless, but could show empty description elements.
+
+**How to avoid:** In templates, check `.Valid` before rendering description/color:
+
+```templ
+if tablo.Description.Valid && tablo.Description.String != "" {
+
{ tablo.Description.String }
+}
+```
+
+**Warning signs:** Empty `
` tags rendered for tablos with no description.
+
+### Pitfall 7: `updated_at` Not Updated on Edit
+
+**What goes wrong:** sqlc generates the UPDATE query exactly as written. If the UPDATE omits `SET updated_at = now()`, the column is never refreshed — it stays at insert time forever.
+
+**How to avoid:** Include `updated_at = now()` explicitly in the UPDATE SQL query. This is simpler than a Postgres trigger and keeps it visible in the query file.
+
+---
+
+## Code Examples
+
+### Migration — 0003_tablos.sql
+
+```sql
+-- migrations/0003_tablos.sql
+-- Phase 3: Tablos CRUD
+
+-- +goose Up
+CREATE TABLE tablos (
+ id uuid PRIMARY KEY DEFAULT gen_random_uuid(),
+ user_id uuid NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+ title text NOT NULL,
+ description text,
+ color text,
+ created_at timestamptz NOT NULL DEFAULT now(),
+ updated_at timestamptz NOT NULL DEFAULT now()
+);
+
+CREATE INDEX tablos_user_id_idx ON tablos(user_id);
+
+-- +goose Down
+DROP TABLE IF EXISTS tablos;
+```
+
+[VERIFIED: CONTEXT.md D-01/D-02, matches backend/migrations/0002_auth.sql style]
+
+### sqlc Queries — tablos.sql
+
+```sql
+-- internal/db/queries/tablos.sql
+
+-- name: ListTablosByUser :many
+SELECT id, user_id, title, description, color, created_at, updated_at
+FROM tablos
+WHERE user_id = $1
+ORDER BY created_at DESC;
+
+-- name: GetTabloByID :one
+SELECT id, user_id, title, description, color, created_at, updated_at
+FROM tablos
+WHERE id = $1;
+
+-- name: InsertTablo :one
+INSERT INTO tablos (user_id, title, description, color)
+VALUES ($1, $2, $3, $4)
+RETURNING id, user_id, title, description, color, created_at, updated_at;
+
+-- name: UpdateTablo :one
+UPDATE tablos
+SET title = $2, description = $3, updated_at = now()
+WHERE id = $1
+RETURNING id, user_id, title, description, color, created_at, updated_at;
+
+-- name: DeleteTablo :exec
+DELETE FROM tablos WHERE id = $1;
+```
+
+Note: `color` is stored but not editable in Phase 3 UI (user can submit it in the create form as plain text). The UpdateTablo query intentionally does not include `color` — color is set at creation only in Phase 3.
+
+[VERIFIED: CONTEXT.md D-02/D-03, matches backend/internal/db/queries/users.sql style]
+
+### Template Structure — tablos.templ (abbreviated)
+
+```go
+// Source: backend/templates/tablos.templ (new file)
+package templates
+
+import (
+ "backend/internal/auth"
+ "backend/internal/db/sqlc"
+ "backend/internal/web/ui"
+)
+
+// TablosDashboard renders the full dashboard (GET /).
+templ TablosDashboard(user *auth.User, csrfToken string, tablos []sqlc.Tablo) {
+ @Layout("Tablos — Xtablo", user, csrfToken) {
+
+
Your Tablos
+ @ui.Button(ui.ButtonProps{
+ Label: "New tablo",
+ Variant: ui.ButtonVariantDefault,
+ Tone: ui.ButtonToneSolid,
+ Size: ui.SizeMD,
+ Type: "button",
+ Attrs: templ.Attributes{
+ "hx-get": "/tablos/new",
+ "hx-target": "#create-form-slot",
+ "hx-swap": "innerHTML",
+ },
+ })
+
+
+
+ if len(tablos) == 0 {
+ @TablosEmptyState()
+ } else {
+ for _, t := range tablos {
+ @TabloCard(t, csrfToken)
+ }
+ }
+
+ }
+}
+```
+
+[VERIFIED: CONTEXT.md D-05, UI-SPEC interaction contract]
+
+---
+
+## Integration Points
+
+### Files That Change in Phase 3
+
+| File | Change | Notes |
+|------|--------|-------|
+| `backend/migrations/0003_tablos.sql` | NEW | goose Up/Down, tablos table + index |
+| `backend/internal/db/queries/tablos.sql` | NEW | 5 sqlc queries |
+| `backend/internal/db/sqlc/tablos.sql.go` | GENERATED | Run `just generate` |
+| `backend/internal/db/sqlc/models.go` | GENERATED | Tablo struct added |
+| `backend/templates/tablos.templ` | NEW | All tablo templates (~300 LOC) |
+| `backend/templates/tablos_templ.go` | GENERATED | Run `just generate` |
+| `backend/internal/web/handlers_tablos.go` | NEW | TablosDeps + 11 handler funcs |
+| `backend/internal/web/router.go` | MODIFIED | Replace IndexHandler, add /tablos* routes, accept TablosDeps |
+| `backend/cmd/web/main.go` | MODIFIED | Construct TablosDeps, pass to NewRouter |
+| `backend/templates/layout.templ` | MODIFIED | Footer text → "Phase 3 · Tablos" |
+| `backend/templates/index.templ` | DELETED or emptied | Dashboard moves to tablos.templ |
+| `backend/internal/web/ui/button.css` | MODIFIED | Add danger + neutral button variants |
+| `backend/tailwind.input.css` | UNCHANGED | Already imports button.css |
+| `backend/internal/tablos/doc.go` | UNCHANGED | Placeholder stays; no impl moves there |
+
+### NewRouter Signature Change
+
+`NewRouter` currently accepts `AuthDeps`. It needs a second deps argument for `TablosDeps` (or `TablosDeps` can be embedded inside an extended deps type). The cleanest approach matching the pattern is a separate `TablosDeps` parameter:
+
+```go
+func NewRouter(pinger Pinger, staticDir string, deps AuthDeps, tabloDeps TablosDeps, csrfKey []byte, env string, trustedOrigins ...string) http.Handler
+```
+
+`cmd/web/main.go` constructs `TablosDeps{Queries: q}` alongside `AuthDeps`.
+
+[VERIFIED: backend/internal/web/router.go, backend/cmd/web/main.go]
+
+---
+
+## State of the Art
+
+| Old Approach | Current Approach | When Changed | Impact |
+|--------------|------------------|--------------|--------|
+| `hx-confirm` (browser confirm()) | Inline server-rendered confirmation fragment | Phase 3 design decision (D-07) | No JS required; server controls copy |
+| Modal dialogs for CRUD | Inline HTMX fragment swaps | Phase 3 design decision (D-05/D-06/D-07) | No new JS/modal components |
+| Soft delete (`deleted_at`) | Hard delete | Phase 3 design decision (D-01) | Simpler queries, irreversible |
+
+**Deprecated in this codebase:**
+- `templates.Index` / `IndexHandler`: The HTMX demo page is replaced by the tablo dashboard. The Phase 1 demo routes (`/demo/time`) remain for now.
+
+---
+
+## Validation Architecture
+
+### Test Framework
+
+| Property | Value |
+|----------|-------|
+| Framework | Go standard `testing` package + `net/http/httptest` |
+| Config file | none — `go test ./...` from `backend/` |
+| Quick run command | `go test ./internal/web/... -run TestTablo` |
+| Full suite command | `just test` (runs `just generate` first, then `go test ./...`) |
+
+### Phase Requirements → Test Map
+
+| Req ID | Behavior | Test Type | Automated Command | File Exists? |
+|--------|----------|-----------|-------------------|-------------|
+| TABLO-01 | GET / renders tablo list for authed user | integration | `go test ./internal/web/... -run TestTabloList` | ❌ Wave 0 |
+| TABLO-01 | GET / returns empty state when no tablos | integration | `go test ./internal/web/... -run TestTabloList_Empty` | ❌ Wave 0 |
+| TABLO-02 | POST /tablos inserts row and returns card fragment | integration | `go test ./internal/web/... -run TestTabloCreate` | ❌ Wave 0 |
+| TABLO-02 | POST /tablos with empty title returns 422 + form errors | integration | `go test ./internal/web/... -run TestTabloCreate_Validation` | ❌ Wave 0 |
+| TABLO-03 | GET /tablos/{id} renders detail for owner | integration | `go test ./internal/web/... -run TestTabloDetail_Owner` | ❌ Wave 0 |
+| TABLO-03 | GET /tablos/{id} returns 404 for non-owner | integration | `go test ./internal/web/... -run TestTabloDetail_NonOwner` | ❌ Wave 0 |
+| TABLO-03 | GET /tablos/{id} returns 404 for invalid UUID | integration | `go test ./internal/web/... -run TestTabloDetail_InvalidID` | ❌ Wave 0 |
+| TABLO-04 | POST /tablos/{id} updates title and returns display fragment | integration | `go test ./internal/web/... -run TestTabloUpdate` | ❌ Wave 0 |
+| TABLO-05 | POST /tablos/{id}/delete removes tablo | integration | `go test ./internal/web/... -run TestTabloDelete` | ❌ Wave 0 |
+| TABLO-05 | GET /tablos/{id}/delete-confirm returns confirm fragment | integration | `go test ./internal/web/... -run TestTabloDeleteConfirm` | ❌ Wave 0 |
+| TABLO-06 | HTMX create returns fragment (not full page) | integration | part of TestTabloCreate | ❌ Wave 0 |
+| TABLO-06 | Non-HTMX create POSTs and redirects 303 | integration | part of TestTabloCreate | ❌ Wave 0 |
+
+### Sampling Rate
+
+- **Per task commit:** `go test ./internal/web/... -run TestTablo`
+- **Per wave merge:** `just test`
+- **Phase gate:** Full suite green before `/gsd-verify-work`
+
+### Wave 0 Gaps
+
+- [ ] `backend/internal/web/handlers_tablos_test.go` — integration tests for all TABLO-01..06 paths (follows handlers_auth_test.go pattern with setupTestDB + real Postgres)
+- [ ] `backend/internal/db/queries/tablos.sql` + re-run `just generate` — sqlc must generate before any test compiles
+- [ ] `backend/migrations/0003_tablos.sql` — test DB setup runs goose.Up which picks up this file automatically
+
+---
+
+## Security Domain
+
+### Applicable ASVS Categories
+
+| ASVS Category | Applies | Standard Control |
+|---------------|---------|-----------------|
+| V2 Authentication | yes (inherited) | gorilla/csrf + session cookie from Phase 2 |
+| V3 Session Management | yes (inherited) | auth.ResolveSession + RequireAuth from Phase 2 |
+| V4 Access Control | yes | Ownership check in every tablo handler — 404 for non-owner |
+| V5 Input Validation | yes | Server-side validation: title required, max 255 chars; color validated if provided |
+| V6 Cryptography | no new requirements | UUID PKs are `gen_random_uuid()` (crypto-random) |
+
+### Known Threat Patterns for This Stack
+
+| Pattern | STRIDE | Standard Mitigation |
+|---------|--------|---------------------|
+| Unauthorized tablo access | Elevation of privilege | `auth.Authed(ctx)` + `tablo.UserID != user.ID → 404` |
+| CSRF on state-changing forms | Tampering | `@ui.CSRFField(csrfToken)` in every form (gorilla/csrf rejects missing token) |
+| UUID enumeration | Information disclosure | UUIDs are random (gen_random_uuid); 404 response for non-owner masks existence |
+| XSS via tablo title/description | Tampering | templ auto-escapes all `{ variable }` interpolations — never use `templ.Raw` |
+| Long-string DoS on title | DoS | Validate `len(title) <= 255` before DB insert |
+| Path traversal via `{id}` | Tampering | `uuid.Parse()` rejects non-UUID strings; parametric route safely bounded |
+
+---
+
+## Environment Availability
+
+Phase 3 is code/migration/template changes only. All runtime dependencies were established in Phase 2:
+
+| Dependency | Required By | Available | Version | Fallback |
+|------------|------------|-----------|---------|----------|
+| Postgres | DB queries | ✓ | (local dev via podman compose) | — |
+| `templ` CLI | Template generation | ✓ | v0.3.1020 (go install) | — |
+| `sqlc` CLI | Query generation | ✓ | v1.31.1 (go install) | — |
+| `goose` CLI | Migrations | ✓ | v3.27.1 (go install) | — |
+| Tailwind standalone | CSS rebuild | ✓ | v4.0.0 (bin/tailwindcss) | — |
+
+[VERIFIED: backend/justfile — all tools pinned and installed via `just bootstrap`]
+
+---
+
+## Assumptions Log
+
+| # | Claim | Section | Risk if Wrong |
+|---|-------|---------|---------------|
+| A1 | `GET /tablos/new` static route takes precedence over `GET /tablos/{id}` parametric in chi v5 when declared first | Architecture Patterns, Pitfall 1 | If wrong: "new" is parsed as a UUID, returns 404. Fix: add prefix `/tablos/ui/new` or restructure routes |
+| A2 | `hx-swap-oob` on a top-level sibling element in the response body correctly triggers an out-of-band swap in HTMX v2 | Pattern 4 | If wrong: form slot not cleared after create. Fix: use `HX-Trigger` + JS event, or restructure to two separate requests |
+| A3 | sqlc generates `pgtype.Text` (not `*string`) for nullable `text` columns when using `pgx/v5` SQL package | Standard Stack | If wrong: nullable fields have different type; template code needs adjustment |
+
+**Risk assessment:** A1 and A3 are LOW risk — chi static-before-parametric ordering is well-documented, and pgtype.Text for nullable text is confirmed by existing models.go pattern (pgtype.Timestamptz). A2 is MEDIUM risk — OOB swap behavior is verified in HTMX docs but the exact template shape needs care.
+
+---
+
+## Open Questions
+
+1. **IndexHandler vs TablosListHandler for GET /**
+ - What we know: Phase 1/2 registered `IndexHandler` for `GET /` which renders the HTMX demo placeholder. CONTEXT.md says `index.templ` "transforms into the tablo dashboard."
+ - What's unclear: Whether to delete `index.templ`/`IndexHandler` entirely and replace with `TablosListHandler`, or to keep both and redirect.
+ - Recommendation: Delete `templates/Index` and `handlers.go`'s `IndexHandler`, replace `GET /` registration in `router.go` with `TablosListHandler(tabloDeps)`. The HTMX demo (`/demo/time`) can remain for Phase 3.
+
+2. **`_method` override for edit vs plain `POST /tablos/{id}/edit`**
+ - What we know: CONTEXT.md marks this as Claude's discretion. chi supports `_method` override via `chimw.MethodOverride` middleware if added.
+ - What's unclear: Whether `_method` override is worth adding to support semantic PATCH.
+ - Recommendation: Use plain `POST /tablos/{id}` with no method override — simpler, no new middleware, fully HTML-form compatible. The route can infer "update" from the POST + path. The UI-SPEC already specifies `hx-post="/tablos/{id}"`.
+
+3. **Color field validation**
+ - What we know: `color` is `text` nullable. CONTEXT.md says "validation at planner's discretion."
+ - What's unclear: Whether to validate hex format or Tailwind class names.
+ - Recommendation: Accept any non-empty string up to 32 chars. Render as inline style `background-color: {{ color }}` with the dot element. If the browser can't parse it, the dot simply won't render a color — no XSS risk because templ escapes it.
+
+---
+
+## Sources
+
+### Primary (HIGH confidence)
+- `backend/internal/web/handlers_auth.go` — verified handler pattern, HTMX detection, redirect pattern
+- `backend/internal/web/router.go` — verified route group structure
+- `backend/internal/web/ui/*.templ`, `*.css` — verified component API and CSS conventions
+- `backend/templates/` — verified templ component shapes
+- `backend/internal/db/sqlc/models.go` — verified pgtype usage pattern
+- `backend/migrations/0002_auth.sql` — verified migration style
+- `backend/internal/db/queries/users.sql` — verified sqlc query style
+- `.planning/phases/03-tablos-crud/03-CONTEXT.md` — locked user decisions
+- `.planning/phases/03-tablos-crud/03-UI-SPEC.md` — UI contract and interaction specs
+- Context7 `/bigskysoftware/htmx` — verified HX-Retarget, HX-Reswap, hx-swap-oob behavior
+
+### Secondary (MEDIUM confidence)
+- Context7 `/websites/templ_guide` — templ attribute and children syntax patterns
+- Context7 `/bigskysoftware/htmx` — hx-swap outerHTML, afterbegin, OOB swap patterns
+
+---
+
+## Metadata
+
+**Confidence breakdown:**
+- Standard Stack: HIGH — all versions verified in go.mod and justfile
+- Architecture: HIGH — all patterns derived from existing codebase
+- HTMX dual-swap: MEDIUM — OOB pattern verified in docs, template shape is new implementation
+- Pitfalls: HIGH — all derived from existing code comments and Phase 2 pitfall list
+
+**Research date:** 2026-05-14
+**Valid until:** 2026-07-14 (stable stack, 60-day window)