refactor(apps)!: delete web-tanstack demo app

Veect retrofit (ADR-027): the product is a hosted SaaS built on
web-next; apps/web-tanstack existed only as template demo surface for
the TanStack Start framework path. This slice removes the app and all
wiring that referenced it:

- turbo.json globalEnv: WEB_TANSTACK_SENTRY_DSN,
  VITE_WEB_TANSTACK_SENTRY_DSN, VITE_GIT_COMMIT_SHA,
  SENTRY_PROJECT_WEB_TANSTACK
- .env.example: the same four DSN/release vars
- generator e2e fixtures that stripped deps from the app's package.json
- coverage diff comment + test fixtures referencing apps/web-tanstack
- app-list entries in README, CLAUDE.md (port table, Sentry projects),
  AGENTS.md (tags, binder list, per-app docs), docs/glossary.md (App)
- pnpm-lock.yaml importer + orphaned transitive deps

Framework-support code in core packages stays: core-trpc's TanStack
provider, core-shared security/tanstack middleware, and the Sentry
react/node init adapters are generic TanStack support, not app wiring.
Prose in guides/ADRs/library traces is story 08 scope.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016j8z4VHjedXDTjEDNg7qHK

turbo.json

@@ -10,14 +10,10 @@
     "WEB_NEXT_SENTRY_DSN",
     "NEXT_PUBLIC_WEB_NEXT_SENTRY_DSN",
     "CMS_SENTRY_DSN",
-    "WEB_TANSTACK_SENTRY_DSN",
-    "VITE_WEB_TANSTACK_SENTRY_DSN",
-    "VITE_GIT_COMMIT_SHA",
     "SENTRY_AUTH_TOKEN",
     "SENTRY_ORG",
     "SENTRY_PROJECT_WEB_NEXT",
     "SENTRY_PROJECT_CMS",
-    "SENTRY_PROJECT_WEB_TANSTACK",
     "SENTRY_TRACES_SAMPLE_RATE",
     "SENTRY_ENVIRONMENT",
     "VERCEL_GIT_COMMIT_SHA",