refactor(projman): extract skills and consolidate commands

Major refactoring of projman plugin architecture:

Skills Extraction (17 new files):
- Extracted reusable knowledge from commands and agents into skills/
- branch-security, dependency-management, git-workflow, input-detection
- issue-conventions, lessons-learned, mcp-tools-reference, planning-workflow
- progress-tracking, repo-validation, review-checklist, runaway-detection
- setup-workflows, sprint-approval, task-sizing, test-standards, wiki-conventions

Command Consolidation (17 → 12 commands):
- /setup: consolidates initial-setup, project-init, project-sync (--full/--quick/--sync)
- /debug: consolidates debug-report, debug-review (report/review modes)
- /test: consolidates test-check, test-gen (run/gen modes)
- /sprint-status: absorbs sprint-diagram via --diagram flag

Architecture Cleanup:
- Remove plugin-level mcp-servers/ symlinks (6 plugins)
- Remove plugin README.md files (12 files, ~2000 lines)
- Update all documentation to reflect new command structure
- Fix documentation drift in CONFIGURATION.md, COMMANDS-CHEATSHEET.md

Commands are now thin dispatchers (~20-50 lines) that reference skills.
Agents reference skills for domain knowledge instead of inline content.

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

plugins/projman/skills/lessons-learned.md

@@ -0,0 +1,139 @@
+---
+name: lessons-learned
+description: Capture and search workflow for lessons learned system
+---
+
+# Lessons Learned System
+
+## Purpose
+
+Defines the workflow for capturing lessons at sprint close and searching them at sprint start/plan.
+
+## When to Use
+
+- **Planner agent**: Search lessons at sprint start
+- **Orchestrator agent**: Capture lessons at sprint close
+- **Commands**: `/sprint-plan`, `/sprint-start`, `/sprint-close`
+
+---
+
+## Searching Lessons (Sprint Start/Plan)
+
+**ALWAYS search for past lessons before planning or executing.**
+
+```python
+search_lessons(
+    repo="org/repo",
+    query="relevant keywords",
+    tags=["technology", "component"],
+    limit=10
+)
+```
+
+**Present findings:**
+```
+Relevant lessons from previous sprints:
+
+📚 Sprint 12: "JWT Token Expiration Edge Cases"
+   Tags: auth, jwt, python
+   Key lesson: Handle token refresh explicitly
+
+📚 Sprint 8: "Service Extraction Boundaries"
+   Tags: architecture, refactoring
+   Key lesson: Define API contracts BEFORE extracting
+```
+
+---
+
+## Capturing Lessons (Sprint Close)
+
+### Interview Questions
+
+Ask these probing questions:
+1. What challenges did you face this sprint?
+2. What worked well and should be repeated?
+3. Were there any preventable mistakes?
+4. Did any technical decisions need adjustment?
+5. What would you do differently?
+
+### Lesson Structure
+
+```markdown
+# Sprint N - [Lesson Title]
+
+## Metadata
+- **Implementation:** [Change VXX.X.X (Impl N)](wiki-link)
+- **Issues:** #XX, #XX
+- **Sprint:** Sprint N
+
+## Context
+[What were you doing?]
+
+## Problem
+[What went wrong / insight / challenge?]
+
+## Solution
+[How did you solve it?]
+
+## Prevention
+[How to avoid in future?]
+
+## Tags
+technology, component, type, pattern
+```
+
+### Creating Lesson
+
+```python
+create_lesson(
+    repo="org/repo",
+    title="Sprint N - Lesson Title",
+    content="[structured content above]",
+    tags=["tag1", "tag2"],
+    category="sprints"
+)
+```
+
+---
+
+## Tagging Strategy
+
+**By Technology:** python, javascript, docker, postgresql, redis, vue, fastapi
+
+**By Component:** backend, frontend, api, database, auth, deploy, testing, docs
+
+**By Type:** bug, feature, refactor, architecture, performance, security
+
+**By Pattern:** infinite-loop, edge-case, integration, boundaries, dependencies
+
+---
+
+## Example Lessons
+
+### Technical Gotcha
+```markdown
+# Sprint 16 - Claude Code Infinite Loop on Validation Errors
+
+## Metadata
+- **Implementation:** [Change V1.2.0 (Impl 1)](wiki-link)
+- **Issues:** #45, #46
+- **Sprint:** Sprint 16
+
+## Context
+Implementing input validation for authentication API.
+
+## Problem
+Claude Code entered infinite loop when pytest validation tests failed.
+The loop occurred because error messages didn't change between attempts.
+
+## Solution
+Added more descriptive error messages specifying what value failed and why.
+
+## Prevention
+- Write validation test errors with specific values
+- If Claude loops, check if errors provide unique information
+- Add loop detection (fail after 3 identical errors)
+
+## Tags
+testing, claude-code, validation, python, pytest
+```