feat: implement agent-os standards system and feature planning tools

- Split CODING_GUIDELINES.md into 19 indexed standards files under .claude/standards/
  - 9 from CODING_GUIDELINES (conventions, powershell, security, api, git, gururmm)
  - 10 from session log tribal knowledge (syncro, ssh, gitea, python, client, gururmm)
- Add .claude/standards/index.yml for cheap relevance-based lookup
- Add /inject-standards command: load targeted standards per task instead of full guidelines
- Add /shape-spec command: pre-implementation spec for GuruRMM features (plan.md,
  shape.md, references.md, standards.md) with mandatory out-of-scope gate
- Add docs/tech-stack.md and docs/mission.md for ClaudeTools API
- Add projects/msp-tools/guru-rmm/docs/tech-stack.md and mission.md for GuruRMM
- Update CLAUDE.md commands table with /inject-standards and /shape-spec

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.claude/CLAUDE.md

@@ -249,6 +249,7 @@ Vault structure: `infrastructure/`, `clients/`, `services/`, `projects/`, `msp-t
 | `/frontend-design` | Modern frontend design (auto-invoke after UI changes) |
 | `/remediation-tool` | M365 breach checks, tenant sweeps, gated remediation |
 | `/feature-request` | Howard submits a GuruRMM feature request — Claude classifies it and messages Mike |
+| `/shape-spec` | Pre-implementation spec for a GuruRMM feature — produces plan.md, shape.md, references.md, standards.md |
 
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