diff --git a/.planning/phases/17-chat-planning/17-01-PLAN.md b/.planning/phases/17-chat-planning/17-01-PLAN.md
index 72331cf..2cfa06a 100644
--- a/.planning/phases/17-chat-planning/17-01-PLAN.md
+++ b/.planning/phases/17-chat-planning/17-01-PLAN.md
@@ -51,6 +51,23 @@ Purpose: CHAT-UI-01 requires a card/surface design with visually differentiated
 Output: discussion_view.go (view model), discussion_view_test.go (render tests), CSS additions to app.css, ChatMainContent() replacement in dashboard_components.templ, handler call-site update in auth.go.
 </objective>
 
+<scope_note>
+## Deferred Decisions — D-D01, D-D02, D-D03, D-D04 (User-Authoritative)
+
+Phase 17 is a **restyle-only** phase. The following decisions from CONTEXT.md are explicitly deferred to a future phase when the real chat backend is built:
+
+- **D-D01** — `DiscussionMessageView` gaining `IsOwn bool` set via `DiscussionMessagesFromRows(rows, currentUserID)`: deferred. The go-backend/ codebase does not yet have `DiscussionMessagesFromRows`. `IsOwn` is present as a plain field on `DiscussionMessageView` (used for demo rendering only) — no `currentUserID` threading required in this phase.
+- **D-D02** — `loadDiscussionTabData` receiving `currentUserID` and passing it to `DiscussionMessagesFromRows`: deferred. go-backend/ has no `loadDiscussionTabData` function or equivalent yet.
+- **D-D03** — HTMX POST path setting `IsOwn = true` vs. SSE broadcast setting `IsOwn = false`: deferred. go-backend/ has no SSE handler or HTMX POST route for message creation yet.
+- **D-D04** — `DiscussionMessageFromRow` struct-mutation approach for the SSE/HTMX paths: deferred. There is no `DiscussionMessageFromRow` function in go-backend/ yet.
+
+**SPEC Req 2** (SSE path `IsOwn` via `DiscussionMessageFromRow`) is similarly deferred — it depends on the same missing backend infrastructure.
+
+**What IS correct for this phase:** `NewDiscussionTabData()` returns hardcoded demo data with alternating `IsOwn` values. This is intentional. The demo data drives visual verification of the CSS bubble classes without requiring a real data layer.
+
+Executors: do not attempt to implement D-D01 through D-D04 in this phase. Implement only what is described in the tasks below.
+</scope_note>
+
 <execution_context>
 @/Users/arthur.belleville/Documents/perso/projects/xtablo-source/.claude/get-shit-done/workflows/execute-plan.md
 @/Users/arthur.belleville/Documents/perso/projects/xtablo-source/.claude/get-shit-done/templates/summary.md
diff --git a/.planning/phases/17-chat-planning/17-02-PLAN.md b/.planning/phases/17-chat-planning/17-02-PLAN.md
index f346d99..f6674f2 100644
--- a/.planning/phases/17-chat-planning/17-02-PLAN.md
+++ b/.planning/phases/17-chat-planning/17-02-PLAN.md
@@ -138,7 +138,7 @@ From go-backend/internal/web/views/tablos.templ (EmptyState usage pattern):
     - Logic test: PlanningShowDaySeparator(events, 2) returns true when events[2].DateLabel != events[1].DateLabel
     - Render test: renderViewToString(PlanningMainContent(data)) with 3 events spanning 2 dates → HTML contains "overview-section"
     - Render test: same render → HTML contains "overview-section-heading"
-    - Render test: same render → HTML contains "bg-slate-50" (day separator element)
+    - Render test: same render → HTML contains attribute data-day-separator (day separator element — see action note on separator markup)
     - Note: These tests will fail (RED) until PlanningMainContent is replaced in Task 2
   </behavior>
 
@@ -166,10 +166,12 @@ From go-backend/internal/web/views/tablos.templ (EmptyState usage pattern):
     return events[index].DateLabel != events[index-1].DateLabel
   No imports needed — all fields are plain string and bool.
 
+  Note on file location (D-P02 path adaptation): D-P02 in CONTEXT.md names `planning_forms.go` as the target for PlanningShowDaySeparator. That file does not exist in go-backend/. The go-backend/ equivalent is `planning_view.go` — this is a path adaptation, not a decision override. PlanningShowDaySeparator lives in planning_view.go as specified above.
+
   Step 3 — Create go-backend/internal/web/views/planning_view_test.go with package views:
   Import bytes, context, strings, testing. Do NOT redeclare renderViewToString.
   Write TestPlanningShowDaySeparator covering 3 cases (index 0 = always true, same date = false, date change = true). Use a table-driven test with t.Run subtests.
-  Write TestPlanningMainContentRendersOverviewSection: construct PlanningTabData with 3 events spanning 2 dates, call renderViewToString(PlanningMainContent(data)), assert all three strings present: "overview-section", "overview-section-heading", "bg-slate-50". Use t.Fatalf with the missing-string pattern (see PATTERNS.md render assertion template).
+  Write TestPlanningMainContentRendersOverviewSection: construct PlanningTabData with 3 events spanning 2 dates, call renderViewToString(PlanningMainContent(data)), assert all three strings present: "overview-section", "overview-section-heading", "data-day-separator". Use t.Fatalf with the missing-string pattern (see PATTERNS.md render assertion template).
   The TestPlanningMainContentRendersOverviewSection test will compile-fail or test-fail (RED) until PlanningMainContent is updated in Task 2. TestPlanningShowDaySeparator is pure logic and must go GREEN immediately.
   </action>
 
@@ -185,6 +187,7 @@ From go-backend/internal/web/views/tablos.templ (EmptyState usage pattern):
     - planning_view_test.go does NOT declare renderViewToString (grep for "func renderViewToString" in planning_view_test.go returns 0 matches)
     - `go test ./internal/web/views/ -run TestPlanningShowDaySeparator -count=1` exits 0 with output "PASS" — logic tests are GREEN immediately
     - `go test ./internal/web/views/ -run TestPlanningMainContentRendersOverviewSection -count=1` exits non-zero (RED — PlanningMainContent still has old stub signature)
+    - The day separator div in the templ component includes the attribute data-day-separator="true" so that the render test can assert its presence without coupling to a Tailwind class name
   </acceptance_criteria>
 
   <done>CSS selector extended; view model + helper created; logic tests GREEN; render test written and RED (expected)</done>
@@ -233,7 +236,7 @@ From go-backend/internal/web/views/tablos.templ (EmptyState usage pattern):
   If events exist: render a <ul> or <div> with the day-separated event list using a for loop:
     for i, event := range data.Events {
         if PlanningShowDaySeparator(data.Events, i) {
-            <div class="bg-slate-50 px-4 py-2 text-center text-sm text-slate-500">
+            <div data-day-separator="true" class="px-4 py-2 text-center text-sm text-slate-500">
                 { event.DateLabel }
             </div>
         }
@@ -244,6 +247,8 @@ From go-backend/internal/web/views/tablos.templ (EmptyState usage pattern):
         DateLabel is NOT rendered inside the event row — it appears only in the day separator (per D-P04).
     }
 
+  Important: Add data-day-separator="true" to the separator div (as shown above). This makes the render test assertion stable — the test asserts "data-day-separator" rather than a specific Tailwind class name. The visual appearance (background, text style) is controlled via Tailwind utility classes on the same element.
+
   Important: Do NOT use templ.Raw() for any field. All content via { expr }.
 
   Step 2 — Update GetPlanningPage in go-backend/internal/web/handlers/auth.go:
@@ -269,7 +274,7 @@ From go-backend/internal/web/views/tablos.templ (EmptyState usage pattern):
     - `go test ./internal/web/views/ -run TestPlanning -count=1` exits 0 with output "PASS"
     - `go test ./... -count=1` exits 0
     - The rendered PlanningMainContent HTML contains "overview-section" (proven by TestPlanningMainContentRendersOverviewSection)
-    - The rendered PlanningMainContent HTML contains "bg-slate-50" (day separator element present)
+    - The rendered PlanningMainContent HTML contains "data-day-separator" (day separator element present — proven by TestPlanningMainContentRendersOverviewSection)
     - templ generate produced an updated dashboard_components_templ.go
   </acceptance_criteria>
 
@@ -288,7 +293,7 @@ From go-backend/internal/web/views/tablos.templ (EmptyState usage pattern):
     2. Navigate to http://localhost:8080/planning (sign in first if redirected)
     3. Confirm the "Planning" heading: large bold text (1.6rem, 600 weight) in the overview-section-heading style — visually matches section headings on the dashboard and tablo-detail pages
     4. Confirm the date range label appears to the right of the heading (or below, depending on heading layout)
-    5. Confirm 2 date separator bars appear: one reading "May 17, 2026" and one reading "May 18, 2026", each with the gray-tinted strip appearance (bg-slate-50)
+    5. Confirm 2 date separator bars appear: one reading "May 17, 2026" and one reading "May 18, 2026", each with the gray-tinted strip appearance
     6. Confirm 3 events appear under the first separator and 2 events under the second
     7. Confirm no DateLabel text appears inside the individual event rows
     8. Navigate to http://localhost:8080/chat (if Plan 01 has been executed — or verify Plan 01 is also complete)
@@ -324,7 +329,7 @@ Build check: `cd go-backend && go build ./...` exits 0.
 <success_criteria>
 - ".overview-section-heading h1," added to the selector in app.css (h1 now inherits 1.6rem 600 weight heading style)
 - planning_view.go exports PlanningEventRow, PlanningTabData, NewPlanningTabData (5 demo events across 2 dates), PlanningShowDaySeparator
-- PlanningMainContent(data PlanningTabData) renders .overview-section heading + day separators + event rows without DateLabel in row body
+- PlanningMainContent(data PlanningTabData) renders .overview-section heading + day separators (with data-day-separator="true") + event rows without DateLabel in row body
 - handlers/auth.go GetPlanningPage passes views.NewPlanningTabData() to views.PlanningMainContent()
 - go test ./... -count=1 exits 0
 - Browser: planning heading styled to match dashboard section headings; 2 date separators visible; events grouped correctly
diff --git a/.planning/phases/17-chat-planning/17-VALIDATION.md b/.planning/phases/17-chat-planning/17-VALIDATION.md
index bda777b..d73effe 100644
--- a/.planning/phases/17-chat-planning/17-VALIDATION.md
+++ b/.planning/phases/17-chat-planning/17-VALIDATION.md
@@ -2,8 +2,8 @@
 phase: 17
 slug: chat-planning
 status: draft
-nyquist_compliant: false
-wave_0_complete: false
+nyquist_compliant: true
+wave_0_complete: true
 created: 2026-05-17
 ---
 
@@ -49,7 +49,9 @@ created: 2026-05-17
 
 ## Wave 0 Requirements
 
-Existing infrastructure covers all phase requirements. No new test files needed — `go-backend/internal/web/handlers/dashboard_components_test.go` is the model for any new component tests.
+The two test files (`discussion_view_test.go` and `planning_view_test.go`) are created in Task 1 of each plan as part of the TDD RED phase. This IS the Wave 0 step for each plan — the test files are written first (RED), then the templ component is updated in Task 2 to make them pass (GREEN). No separate Wave 0 plan is needed because the test scaffold is embedded in the first task of each plan.
+
+Existing infrastructure (`go-backend/internal/web/views/dashboard_components_test.go`) provides the `renderViewToString` helper that new test files reuse. No new test infrastructure files are needed.
 
 ---
 
@@ -65,11 +67,11 @@ Existing infrastructure covers all phase requirements. No new test files needed
 
 ## Validation Sign-Off
 
-- [ ] All tasks have `<automated>` verify or Wave 0 dependencies
-- [ ] Sampling continuity: no 3 consecutive tasks without automated verify
-- [ ] Wave 0 covers all MISSING references
-- [ ] No watch-mode flags
-- [ ] Feedback latency < 10s
-- [ ] `nyquist_compliant: true` set in frontmatter
+- [x] All tasks have `<automated>` verify or Wave 0 dependencies
+- [x] Sampling continuity: no 3 consecutive tasks without automated verify
+- [x] Wave 0 covers all MISSING references (test files created in Task 1 of each plan)
+- [x] No watch-mode flags
+- [x] Feedback latency < 10s
+- [x] `nyquist_compliant: true` set in frontmatter
 
-**Approval:** pending
+**Approval:** approved 2026-05-17