docs(01-03): complete .intunewin builder plan

- Add 01-03-SUMMARY.md with byte-level format validation results
- Update STATE.md: progress 33%, decisions recorded, session updated
- Update ROADMAP.md: phase 1 in progress (1/3 summaries)
- Mark INFRA-02 complete in REQUIREMENTS.md

.planning/STATE.md

@@ -3,14 +3,14 @@ gsd_state_version: 1.0
 milestone: v1.0
 milestone_name: milestone
 status: planning
-stopped_at: Phase 1 context gathered
-last_updated: "2026-04-10T08:56:16.637Z"
+stopped_at: Completed 01-03-PLAN.md
+last_updated: "2026-04-10T09:26:32.100Z"
 last_activity: 2026-04-10 — Roadmap created, 5 phases derived from 27 requirements
 progress:
   total_phases: 5
   completed_phases: 0
-  total_plans: 0
-  completed_plans: 0
+  total_plans: 3
+  completed_plans: 1
   percent: 0
 ---
 
@@ -50,6 +50,7 @@ Progress: [░░░░░░░░░░] 0%
 - Trend: -
 
 *Updated after each plan completion*
+| Phase 01 P03 | 7 | 1 tasks | 4 files |
 
 ## Accumulated Context
 
@@ -60,6 +61,8 @@ Recent decisions affecting current work:
 
 - Phase 1: .intunewin reimplemented natively in Python (IntuneWinAppUtil.exe is a Windows PE binary, cannot run in Linux container)
 - Phase 1: Stack is Python 3.12 + FastAPI + Jinja2 + HTMX + SQLite + pycryptodome
+- [Phase 01]: IV is 16 bytes for .intunewin AES-256-CBC (not 32 as documented in STACK.md — corrected from RESEARCH.md)
+- [Phase 01]: Inner .intunewin ZIP uses DEFLATE compression; outer ZIP uses STORED (matches C# reference implementation)
 
 ### Pending Todos
 
@@ -72,6 +75,6 @@ None yet.
 
 ## Session Continuity
 
-Last session: 2026-04-10T08:56:16.634Z
-Stopped at: Phase 1 context gathered
-Resume file: .planning/phases/01-foundation/01-CONTEXT.md
+Last session: 2026-04-10T09:26:23.280Z
+Stopped at: Completed 01-03-PLAN.md
+Resume file: None