feat: Add self-contained orchestration templates and guide

Makes Mosaic Stack self-contained for orchestration - no external dependencies.

New files:
- docs/claude/orchestrator.md - Platform-specific orchestrator protocol
- docs/templates/ - Bootstrap templates for tasks.md, learnings, reports

Templates:
- orchestrator/tasks.md.template - Task tracking scaffold
- orchestrator/orchestrator-learnings.json.template - Variance tracking
- orchestrator/orchestrator-learnings.schema.md - JSON schema docs
- orchestrator/phase-issue-body.md.template - Gitea issue body
- orchestrator/compaction-summary.md.template - 60% checkpoint format
- reports/review-report-scaffold.sh - Creates report directory
- scratchpad.md.template - Per-task working document

Updated CLAUDE.md:
- References local docs/claude/orchestrator.md instead of ~/.claude/
- Added Platform Templates section pointing to docs/templates/

This enables deployment without requiring user-level ~/.claude/ configuration.

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

docs/templates/orchestrator/orchestrator-learnings.json.template

@@ -0,0 +1,10 @@
+{
+  "schema_version": "1.0",
+  "project": "${PROJECT}",
+  "milestone": "${MILESTONE}",
+  "created_at": "${CURRENT_DATETIME}",
+  "learnings": [],
+  "phase_summaries": [],
+  "proposed_adjustments": [],
+  "investigation_queue": []
+}