[Sprint V04.1.0] feat: Add cross-linking between issues, wiki, and lessons

- Add Metadata section to lesson structure with Implementation link
- Update lesson examples to include metadata with wiki reference
- Enable bidirectional traceability: lessons ↔ implementation pages

Phase 3 of V04.1.0 Wiki-Based Planning Enhancement.
Closes #163

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

plugins/projman/commands/sprint-close.md

@@ -89,6 +89,11 @@ Lessons should follow this structure:
 ```markdown
 # Sprint X - [Lesson Title]
 
+## Metadata
+- **Implementation:** [Change VXX.X.X (Impl N)](wiki-link)
+- **Issues:** #45, #46, #47
+- **Sprint:** Sprint X
+
 ## Context
 [What were you trying to do? What was the sprint goal?]
 
@@ -105,12 +110,19 @@ Lessons should follow this structure:
 [Comma-separated tags for search: technology, component, type]
 ```
 
+**IMPORTANT:** Always include the Implementation link in the Metadata section. This enables bidirectional traceability between lessons and the work that generated them.
+
 ## Example Lessons Learned
 
 **Example 1: Technical Gotcha**
 ```markdown
 # Sprint 16 - Claude Code Infinite Loop on Validation Errors
 
+## Metadata
+- **Implementation:** [Change V1.2.0 (Impl 1)](https://gitea.example.com/org/repo/wiki/Change-V1.2.0%3A-Proposal-(Implementation-1))
+- **Issues:** #45, #46
+- **Sprint:** Sprint 16
+
 ## Context
 Implementing input validation for authentication API endpoints.
 
@@ -137,6 +149,11 @@ testing, claude-code, validation, python, pytest, debugging
 ```markdown
 # Sprint 14 - Extracting Services Too Early
 
+## Metadata
+- **Implementation:** [Change V2.0.0 (Impl 1)](https://gitea.example.com/org/repo/wiki/Change-V2.0.0%3A-Proposal-(Implementation-1))
+- **Issues:** #32, #33, #34
+- **Sprint:** Sprint 14
+
 ## Context
 Planning to extract Intuit Engine service from monolith.