feat(07-01): wire embed.FS into NewRouter and RunMigrations into cmd/web/main.go

- backend/internal/web/router.go: staticDir string -> staticFS fs.FS; /healthz uses HealthzHandler(); /readyz registered with ReadyzHandler(pinger); embedded FS served via fs.Sub()
- backend/cmd/web/main.go: import assets "backend"; db.RunMigrations(ctx, pool, assets.Migrations) before router; web.NewRouter now receives assets.Static
- All *_test.go NewRouter call sites updated from "./static" to os.DirFS("./static"); "os" import added where missing

backend/cmd/web/main.go

@@ -1,7 +1,7 @@
 // Command web is the Phase 1 walking-skeleton HTTP server. It loads env,
-// builds a slog handler, opens a pgxpool, mounts the chi router, and serves
+// builds a slog handler, opens a pgxpool, runs goose migrations, mounts the
-// /, /healthz, /demo/time, and /static/* with graceful shutdown on
+// chi router, and serves /, /healthz, /readyz, /demo/time, and /static/* with
-// SIGINT/SIGTERM (CONTEXT D-19).
+// graceful shutdown on SIGINT/SIGTERM (CONTEXT D-19, D-10, DEPLOY-03/04).
 //
 // No .env parser lives here — `.env` is exported into the process
 // environment by `just dev`; production injects real env vars (D-15).
@@ -18,6 +18,7 @@ import (
 	"syscall"
 	"time"
 
+	assets "backend"
 	"backend/internal/auth"
 	"backend/internal/db"
 	"backend/internal/db/sqlc"
@@ -68,6 +69,13 @@ func main() {
 		os.Exit(1)
 	}
 
+	// D-10: run goose migrations from the embedded FS before constructing the
+	// router. goose.Up is idempotent — already-applied migrations are skipped.
+	if err := db.RunMigrations(ctx, pool, assets.Migrations); err != nil {
+		slog.Error("migrations failed", "err", err)
+		os.Exit(1)
+	}
+
 	q := sqlc.New(pool)
 	store := auth.NewStore(q)
 	secure := env != "development" && env != "dev"
@@ -113,7 +121,8 @@ func main() {
 
 	fileDeps := web.FilesDeps{Queries: q, Files: filesStore, MaxUploadMB: maxUploadMB}
 
-	router := web.NewRouter(pool, "./static", deps, tabloDeps, taskDeps, fileDeps, csrfKey, env)
+	// D-09: pass the embedded static FS — binary has zero runtime file dependencies.
+	router := web.NewRouter(pool, assets.Static, deps, tabloDeps, taskDeps, fileDeps, csrfKey, env)
 
 	srv := &http.Server{
 		Addr:    ":" + port,

backend/internal/web/csrf_test.go

@@ -22,7 +22,7 @@ func newTestRouterWithCSRF(q *sqlc.Queries, store *auth.Store) http.Handler {
 		csrfKey[i] = byte(i + 1)
 	}
 	deps := AuthDeps{Queries: q, Store: store, Secure: false}
-	return NewRouter(stubPinger{}, "./static", deps, TablosDeps{Queries: q}, TasksDeps{Queries: q}, FilesDeps{Queries: q}, csrfKey, "dev", "localhost")
+	return NewRouter(stubPinger{}, os.DirFS("./static"), deps, TablosDeps{Queries: q}, TasksDeps{Queries: q}, FilesDeps{Queries: q}, csrfKey, "dev", "localhost")
 }
 
 // extractCSRFToken performs a GET request and extracts the _csrf token from the

backend/internal/web/handlers_auth_test.go

@@ -9,6 +9,7 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"net/url"
+	"os"
 	"strings"
 	"testing"
 	"time"
@@ -33,14 +34,14 @@ var testCSRFKey = func() []byte {
 // Referer header are accepted.
 func newTestRouter(q *sqlc.Queries, store *auth.Store) http.Handler {
 	deps := AuthDeps{Queries: q, Store: store, Secure: false}
-	return NewRouter(stubPinger{}, "./static", deps, TablosDeps{Queries: q}, TasksDeps{Queries: q}, FilesDeps{Queries: q}, testCSRFKey, "dev", "localhost")
+	return NewRouter(stubPinger{}, os.DirFS("./static"), deps, TablosDeps{Queries: q}, TasksDeps{Queries: q}, FilesDeps{Queries: q}, testCSRFKey, "dev", "localhost")
 }
 
 // newTestRouterWithLimiter builds a router with an injected LimiterStore,
 // enabling rate-limit tests to use a fake clock.
 func newTestRouterWithLimiter(q *sqlc.Queries, store *auth.Store, rl *auth.LimiterStore) http.Handler {
 	deps := AuthDeps{Queries: q, Store: store, Secure: false, Limiter: rl}
-	return NewRouter(stubPinger{}, "./static", deps, TablosDeps{Queries: q}, TasksDeps{Queries: q}, FilesDeps{Queries: q}, testCSRFKey, "dev", "localhost")
+	return NewRouter(stubPinger{}, os.DirFS("./static"), deps, TablosDeps{Queries: q}, TasksDeps{Queries: q}, FilesDeps{Queries: q}, testCSRFKey, "dev", "localhost")
 }
 
 // getCSRFToken performs a GET request to path and extracts the CSRF token

backend/internal/web/handlers_files_test.go

@@ -18,6 +18,7 @@ import (
 	"mime/multipart"
 	"net/http"
 	"net/http/httptest"
+	"os"
 	"strings"
 	"testing"
 
@@ -59,7 +60,7 @@ func newFileTestRouter(q *sqlc.Queries, store *auth.Store, fileStore files.FileS
 	tabloDeps := TablosDeps{Queries: q}
 	taskDeps := TasksDeps{Queries: q}
 	fileDeps := FilesDeps{Queries: q, Files: fileStore, MaxUploadMB: 25}
-	return NewRouter(stubPinger{}, "./static", authDeps, tabloDeps, taskDeps, fileDeps, testCSRFKey, "dev", "localhost")
+	return NewRouter(stubPinger{}, os.DirFS("./static"), authDeps, tabloDeps, taskDeps, fileDeps, testCSRFKey, "dev", "localhost")
 }
 
 // ---- TestFileUpload (FILE-01, FILE-02) ----
@@ -164,7 +165,7 @@ func TestFileUploadTooLarge(t *testing.T) {
 	tabloDeps := TablosDeps{Queries: q}
 	taskDeps := TasksDeps{Queries: q}
 	fileDeps := FilesDeps{Queries: q, Files: stub, MaxUploadMB: 1}
-	router := NewRouter(stubPinger{}, "./static", authDeps, tabloDeps, taskDeps, fileDeps, testCSRFKey, "dev", "localhost")
+	router := NewRouter(stubPinger{}, os.DirFS("./static"), authDeps, tabloDeps, taskDeps, fileDeps, testCSRFKey, "dev", "localhost")
 
 	user := preInsertUser(t, ctx, q, "filelarge@example.com", "correct-horse-12")
 	tablo, err := q.InsertTablo(ctx, sqlc.InsertTabloParams{

backend/internal/web/handlers_tablos_test.go

@@ -13,6 +13,7 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"net/url"
+	"os"
 	"strings"
 	"testing"
 
@@ -26,7 +27,7 @@ import (
 func newTabloTestRouter(q *sqlc.Queries, store *auth.Store) http.Handler {
 	authDeps := AuthDeps{Queries: q, Store: store, Secure: false}
 	tabloDeps := TablosDeps{Queries: q}
-	return NewRouter(stubPinger{}, "./static", authDeps, tabloDeps, TasksDeps{Queries: q}, FilesDeps{Queries: q}, testCSRFKey, "dev", "localhost")
+	return NewRouter(stubPinger{}, os.DirFS("./static"), authDeps, tabloDeps, TasksDeps{Queries: q}, FilesDeps{Queries: q}, testCSRFKey, "dev", "localhost")
 }
 
 // loginUser signs up a user and returns the session cookie set after signup.

backend/internal/web/handlers_tasks_test.go

@@ -15,6 +15,7 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"net/url"
+	"os"
 	"strings"
 	"testing"
 
@@ -29,7 +30,7 @@ func newTaskTestRouter(q *sqlc.Queries, store *auth.Store) http.Handler {
 	authDeps := AuthDeps{Queries: q, Store: store, Secure: false}
 	tabloDeps := TablosDeps{Queries: q}
 	taskDeps := TasksDeps{Queries: q}
-	return NewRouter(stubPinger{}, "./static", authDeps, tabloDeps, taskDeps, FilesDeps{Queries: q}, testCSRFKey, "dev", "localhost")
+	return NewRouter(stubPinger{}, os.DirFS("./static"), authDeps, tabloDeps, taskDeps, FilesDeps{Queries: q}, testCSRFKey, "dev", "localhost")
 }
 
 // ---- TestTasksKanbanRenders (TASK-01) ----

backend/internal/web/router.go

@@ -2,6 +2,7 @@ package web
 
 import (
 	"context"
+	"io/fs"
 	"log/slog"
 	"net/http"
 	"time"
@@ -12,7 +13,7 @@ import (
 	chimw "github.com/go-chi/chi/v5/middleware"
 )
 
-// Pinger is the contract /healthz uses to probe the data plane. *pgxpool.Pool
+// Pinger is the contract /readyz uses to probe the data plane. *pgxpool.Pool
 // satisfies this interface out of the box, which is why cmd/web passes the
 // pool directly to NewRouter (no adapter required).
 type Pinger interface {
@@ -29,10 +30,10 @@ type Pinger interface {
 //  5. auth.ResolveSession (reads session cookie, attaches user to context) — D-24
 //  6. auth.Mount (gorilla/csrf — MUST come after ResolveSession, before routes) — D-24, Pitfall 7
 //
-// Routes: GET / · GET /healthz · GET /demo/time · GET /static/*
+// Routes: GET / · GET /healthz (liveness) · GET /readyz (readiness) · GET /demo/time · GET /static/*
 //         GET /signup (auth pages, behind RedirectIfAuthed) · POST /signup.
-// staticDir is the on-disk path served at /static/*; path traversal is
+// staticFS is the embedded FS (or os.DirFS in tests) served at /static/*; the
-// blocked by http.Dir's default behavior (T-01-08).
+// embedded FS pattern blocks path traversal at the http.FS layer (T-01-08).
 //
 // deps.Store may be nil during unit tests for Phase 1 routes (those routes
 // never exercise session resolution). ResolveSession guards against nil Store.
@@ -44,7 +45,7 @@ type Pinger interface {
 // trustedOrigins is an optional list of additional origins for the CSRF
 // referer check (used in integration tests to allow localhost requests without
 // a Referer header). In production, pass no extra args — leave empty.
-func NewRouter(pinger Pinger, staticDir string, deps AuthDeps, tabloDeps TablosDeps, taskDeps TasksDeps, fileDeps FilesDeps, csrfKey []byte, env string, trustedOrigins ...string) http.Handler {
+func NewRouter(pinger Pinger, staticFS fs.FS, deps AuthDeps, tabloDeps TablosDeps, taskDeps TasksDeps, fileDeps FilesDeps, csrfKey []byte, env string, trustedOrigins ...string) http.Handler {
 	r := chi.NewRouter()
 	r.Use(RequestIDMiddleware)
 	r.Use(chimw.RealIP)
@@ -114,11 +115,21 @@ func NewRouter(pinger Pinger, staticDir string, deps AuthDeps, tabloDeps TablosD
 		r.Post("/tablos/{id}/files/{file_id}/delete", FileDeleteHandler(fileDeps))
 	})
 
-	r.Get("/healthz", HealthzHandler(pinger))
+	// Liveness probe (D-12): always 200, no DB contact.
+	r.Get("/healthz", HealthzHandler())
+	// Readiness probe (D-13): probes DB; 200 when ready, 503 when degraded.
+	r.Get("/readyz", ReadyzHandler(pinger))
 	r.Get("/demo/time", DemoTimeHandler(func() time.Time { return time.Now() }))
 
-	fs := http.StripPrefix("/static/", http.FileServer(http.Dir(staticDir)))
+	// Serve embedded static assets. Sub to strip the "static/" prefix from the
-	r.Get("/static/*", fs.ServeHTTP)
+	// embedded path so /static/tailwind.css maps to static/tailwind.css inside
+	// the FS. The "fs" local name is avoided to prevent shadowing the "io/fs" import.
+	sub, err := fs.Sub(staticFS, "static")
+	if err != nil {
+		panic("router: failed to sub static FS: " + err.Error())
+	}
+	fileHandler := http.StripPrefix("/static/", http.FileServer(http.FS(sub)))
+	r.Get("/static/*", fileHandler.ServeHTTP)
 
 	return r
 }