feat(04-05): wire codebase intel injection into planner

- Read .planning/intel/summary.md into INTEL_CONTENT in Step 7
- Add {intel_content} placeholder to planning_context in Step 8
- Planner now receives dependency hotspots, module types at planning time

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

commands/gsd/plan-phase.md

@@ -249,6 +249,9 @@ RESEARCH_CONTENT=$(cat "${PHASE_DIR}"/*-RESEARCH.md 2>/dev/null)
 # Gap closure files (only if --gaps mode)
 VERIFICATION_CONTENT=$(cat "${PHASE_DIR}"/*-VERIFICATION.md 2>/dev/null)
 UAT_CONTENT=$(cat "${PHASE_DIR}"/*-UAT.md 2>/dev/null)
+
+# Codebase intelligence (if exists)
+INTEL_CONTENT=$(cat .planning/intel/summary.md 2>/dev/null)
 ```
 
 ## 8. Spawn gsd-planner Agent
@@ -289,6 +292,9 @@ Fill prompt with inlined content and spawn:
 {verification_content}
 {uat_content}
 
+**Codebase Intel (if exists):**
+{intel_content}
+
 </planning_context>
 
 <downstream_consumer>