Release 0.2.0: graduation merge race fix + VITE_APP_NAME + versioning infrastructure

- Fix §13.3 step 4 race against Gitea's async mergeability
  computation: gitea.wait_for_mergeable polls the mergeable
  field before calling merge, and bot._merge_with_retry rides
  out the transient 'Please try again later' response.
- Frontend now requires VITE_APP_NAME at build time
  (frontend/vite.config.js fails the build if unset). Header
  brand, landing H1, and browser title read the deployment's
  configured name.
- Establish framework versioning: VERSION (canonical) +
  frontend/package.json#version mirror; CHANGELOG.md as the
  release log with RFC 2119 / 8174 normative-language
  upgrade-steps; SPEC.md §20 as the binding policy; CLAUDE.md
  capturing the separation-of-concerns rule; docs/DEPLOYMENTS.md
  as the downstream operating manual; docs/QUICKSTART-VISION.md
  staking the future one-command-deploy capability.
- Surgical fix to SPEC.md opening so the spec no longer asserts
  OHM is the corpus the framework produces.
- SPEC.md §19.2 gains the 'Deployment-supplied subject framing'
  candidate that drives the 0.3.0 release.

frontend/.env.example

@@ -0,0 +1,15 @@
+# Frontend build-time configuration. Copy to `frontend/.env` and fill in.
+#
+# Vite picks up VITE_* variables from these files at build (`npm run build`)
+# and dev (`npm run dev`) time. Real `.env` files are gitignored; only this
+# `.env.example` is committed.
+
+# The user-visible name of this deployment. Used as the browser tab title,
+# the header brand, and the landing page H1. Required — the framework
+# ships no default on purpose so each deployment names itself. If unset,
+# `npm run build` fails with a clear message.
+#
+# Examples:
+#   VITE_APP_NAME=Wiggleverse RFC
+#   VITE_APP_NAME=Wiggleverse Open Human Model
+VITE_APP_NAME=