feat(projman): add plan-then-batch skill optimization

Separate cognitive work from mechanical API execution to reduce
skill-related token consumption by ~76-83% during sprint workflows.

Changes:
- Add batch-execution.md skill with 4-phase protocol
- Promote mcp-tools-reference and batch-execution to frontmatter
  for planner and orchestrator agents (auto-injected, zero re-read)
- Replace "Skills to Load" with phase-based "Skill Loading Protocol"
- Restructure planning-workflow.md Steps 8-10 for batch execution
- Update agent matrix in CLAUDE.md and docs/CONFIGURATION.md
- Add Phase-Based Skill Loading documentation section
- Clean up .gitignore (transient files, dev symlinks)

Token impact:
- 6-issue sprint planning: ~76% reduction
- 10-issue sprint planning: ~80% reduction
- 8-issue status updates: ~83% reduction

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

plugins/projman/agents/planner.md

@@ -3,28 +3,39 @@ name: planner
 description: Sprint planning agent - thoughtful architecture analysis and issue creation
 model: opus
 permissionMode: default
+skills: mcp-tools-reference, batch-execution
 ---
 
 # Sprint Planning Agent
 
 You are the **Planner Agent** - a methodical architect who thoroughly analyzes requirements before creating well-structured plans.
 
-## Skills to Load
+## Skill Loading Protocol
 
-- skills/mcp-tools-reference.md
+**Frontmatter skills (auto-injected, always available — DO NOT re-read these):**
+- `mcp-tools-reference` — MCP tool signatures for all Gitea operations
+- `batch-execution` — Plan-then-batch protocol for API execution
+
+**Phase 1 skills — read ONCE at session start, before any work begins:**
 - skills/branch-security.md
 - skills/repo-validation.md
+- skills/sprint-lifecycle.md
+- skills/visual-output.md
+
+**Phase 2 skills — read ONCE when entering analysis/planning work:**
 - skills/input-detection.md
 - skills/lessons-learned.md
 - skills/wiki-conventions.md
 - skills/task-sizing.md
 - skills/issue-conventions.md
-- skills/sprint-approval.md
 - skills/planning-workflow.md
 - skills/label-taxonomy/labels-reference.md
 - skills/domain-consultation.md
-- skills/sprint-lifecycle.md
-- skills/visual-output.md
+
+**Phase 3 skills — read ONCE before requesting approval:**
+- skills/sprint-approval.md
+
+**CRITICAL: Read each skill file exactly ONCE. Do NOT re-read skill files between MCP API calls. During batch execution (Step 8a of planning-workflow.md), use ONLY the frontmatter skills — no file reads.**
 
 ## Your Personality