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/task-sizing.md

@@ -0,0 +1,104 @@
+---
+name: task-sizing
+description: Task sizing rules and mandatory breakdown requirements
+---
+
+# Task Sizing Rules
+
+## Purpose
+
+Defines effort estimation rules and enforces task breakdown requirements.
+
+## When to Use
+
+- **Planner agent**: When creating issues during sprint planning
+- **Orchestrator agent**: When reviewing task scope during sprint start
+- **Code Reviewer agent**: When flagging oversized tasks
+
+---
+
+## Sizing Matrix
+
+| Effort | Files | Checklist Items | Max Tool Calls | Agent Scope |
+|--------|-------|-----------------|----------------|-------------|
+| **XS** | 1 file | 0-2 items | ~30 | Single function/fix |
+| **S** | 1 file | 2-4 items | ~50 | Single file feature |
+| **M** | 2-3 files | 4-6 items | ~80 | Multi-file feature |
+| **L** | MUST BREAK DOWN | - | - | Too large |
+| **XL** | MUST BREAK DOWN | - | - | Way too large |
+
+---
+
+## CRITICAL: L/XL Tasks MUST Be Broken Down
+
+**Why:**
+- Agents running 400+ tool calls take 1+ hour with no visibility
+- Large tasks lack clear completion criteria
+- Debugging failures is extremely difficult
+- Small tasks enable parallel execution
+
+---
+
+## Scoping Checklist
+
+1. Can this be completed in one file? → XS or S
+2. Does it touch 2-3 files? → M (maximum for single task)
+3. Does it touch 4+ files? → MUST break down
+4. Would you estimate 50+ tool calls? → MUST break down
+5. Does it require complex decision-making mid-task? → MUST break down
+
+---
+
+## Breakdown Example
+
+### BAD (L - too broad)
+```
+[Sprint 3] feat: Implement schema diff detection hook
+Labels: Efforts/L
+- Hook skeleton
+- Pattern detection
+- Warning output
+- Integration
+```
+
+### GOOD (broken into S tasks)
+```
+[Sprint 3] feat: Create hook skeleton
+Labels: Efforts/S
+- [ ] Create hook file with standard header
+- [ ] Add file type detection for SQL
+- [ ] Exit 0 (non-blocking)
+
+[Sprint 3] feat: Add DROP/ALTER pattern detection
+Labels: Efforts/S
+- [ ] Detect DROP COLUMN/TABLE/INDEX
+- [ ] Detect ALTER TYPE changes
+- [ ] Detect RENAME operations
+
+[Sprint 3] feat: Add warning output formatting
+Labels: Efforts/S
+- [ ] Format breaking change warnings
+- [ ] Add hook prefix to output
+
+[Sprint 3] chore: Register hook in hooks.json
+Labels: Efforts/XS
+- [ ] Add PostToolUse:Edit hook entry
+```
+
+---
+
+## Enforcement
+
+**The planner MUST refuse to create L/XL tasks without breakdown.**
+
+If user requests a large task:
+```
+This task appears to be L/XL sized (touches 4+ files, estimated 100+ tool calls).
+
+L/XL tasks MUST be broken down into S/M subtasks because:
+- Agents need clear, completable units of work
+- Parallel execution requires smaller tasks
+- Progress visibility requires frequent checkpoints
+
+Let me break this down into smaller tasks...
+```