docs(18-01): complete InitiativeHeader & ProgressPanel plan

Tasks completed: 2/2
- InitiativeHeader with back button, name, status badge, dates
- ProgressPanel with progress bar and phase/task counts

SUMMARY: .planning/phases/18-initiative-detail/18-01-SUMMARY.md

.planning/STATE.md

@@ -9,19 +9,19 @@ See: .planning/PROJECT.md (updated 2026-02-04)
 
 ## Current Position
 
-Phase: 17 of 21 (Initiative Dashboard)
-Plan: 4 of 4 in current phase (COMPLETE)
-Status: Phase 17 complete
-Last activity: 2026-02-04 - Completed 17-04-PLAN.md
+Phase: 18 of 21 (Initiative Detail)
+Plan: 2 of 4 in current phase
+Status: In progress
+Last activity: 2026-02-04 - Completed 18-02-PLAN.md
 
 Progress: █████████░ 97%
 
 ## Performance Metrics
 
 **Velocity:**
-- Total plans completed: 65
+- Total plans completed: 67
 - Average duration: 3 min
-- Total execution time: 181 min
+- Total execution time: 188 min
 
 **By Phase (v1.0):**
 
@@ -201,6 +201,8 @@ Recent decisions affecting current work:
 - 17-03: shadcn CLI @/ dir bug workaround applied again (same as 16-04)
 - 17-04: Dashboard page owns create action (Option A) — keeps AppLayout generic for other pages
 - 17-04: Route param is $id matching existing $id.tsx file route definition
+- 18-01: Reuse SerializedInitiative shape for header props (dates as ISO strings)
+- 18-01: Actions button disabled as placeholder — wired in Plan 04
 
 ### Pending Todos
 
@@ -223,5 +225,5 @@ None.
 ## Session Continuity
 
 Last session: 2026-02-04
-Stopped at: Completed 17-04-PLAN.md (Phase 17 complete)
+Stopped at: Completed 18-01-PLAN.md
 Resume file: None