feat(standards): add versioning + changelog standard, release templates, and Drone version guard

Add lib page 11 (SemVer contract, pre-1.0 rule, tag==version invariant, Keep a Changelog), the releasing wiki runbook, and canonical release templates (CHANGELOG.md, VERSION). Vendor them into the MCP bundle as templates/release + release.json and expose registry://release with list/get tools. Add a changelog component to the app template. Enforce the tag<->version contract in both Drone shapes: Type A check-version and the backfill loop verify pyproject version; Type B adds a VERSION guard step.

standards/mcp/components.json

@@ -186,6 +186,12 @@
       "placeholder": "",
       "description": "Packaging + dependency pins."
     },
+    {
+      "kind": "changelog",
+      "path": "CHANGELOG.md",
+      "placeholder": "",
+      "description": "Keep a Changelog file with an [Unreleased] section (versioning standard)."
+    },
     {
       "kind": "dockerfile",
       "path": "Dockerfile",