Migrate admin routes from Hono to TanStack Start

[InfinityBowman]

Context

Tier 3 of the Hono → TanStack Start consolidation. Blocked on / runs alongside #484 (billing). Migration recipe: `packages/docs/audits/hono-to-tanstack-migration.md`.

Scope

Files in `packages/workers/src/routes/admin/`, recommended order smallest-first:

• `index.ts` (34 lines — router wiring)
• `orgs.ts` (393 lines)
• `storage.ts` (525 lines)
• `stats.ts` (665 lines)
• `projects.ts` (772 lines)
• `billing-observability.ts` (788 lines)
• `stripe-tools.ts` (808 lines)
• `database.ts` (997 lines)
• `users.ts` (1,092 lines)
• `billing.ts` (1,195 lines)

~7,200 lines total across 10 files.

Per-file recipe

1. Create TanStack file route(s) under `packages/web/src/routes/api/admin/`
2. These routes need an admin-role guard. If not already in `packages/web/src/server/guards/`, add one (probably `requireAdmin(request, env)` checking `user.role === 'admin'`)
3. Port tests into co-located `tests/*.server.test.ts`
4. Strip the Hono route to an empty stub
5. Delete the corresponding Hono test file
6. Run both test suites and typechecks

Notes

• Most admin routes are read-only dashboards → faster per-line than billing
• Several files are large because they bundle many endpoints; consider splitting one Hono file into multiple TanStack files along endpoint boundaries
• `billing.ts` and `billing-observability.ts` may share Stripe helpers with the billing webhook tree — don't strip those helpers

Suggested branch

`migrate-admin-routes`

[coderabbitai]

🔗 Related PRs

#160 - add r2 document management to admin dashboard [merged]
#246 - Migrate await from api.corates.org [merged]
#288 - 244 partial zod openapi hono [merged]
#296 - 295 backend typescript migration [merged]
#463 - add admin route for checking project storage usage [merged]

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