Replace the v1 route convention with an explicit route config

[engleek]

What

app/routes.ts now lists every route explicitly with route() / index() from @react-router/dev/routes, instead of using remixRoutesOptionAdapter(createRoutesFromFolders). @remix-run/v1-route-convention and @react-router/remix-routes-option-adapter are removed from package.json.

The config follows the v1 folder convention:

• dots in a file name are path segments (event.$id.edit.jsx → event/:id/edit, at the top level)
• only a sibling folder creates nesting: event.$id/* and game.$id/* are children of event/:id and game/:id; *.changes/ holds index + :revisionId children
• $.jsx is the * splat, and admin/ and auth/ are plain path prefixes

@react-router/fs-routes was not used because its flat-routes convention would nest event.$id.changes and event.$id.edit under event.$id, which would change the nesting.

Why

@remix-run/v1-route-convention pulled in @remix-run/dev@1.19.3. Removing it drops 576 packages from the lockfile (no packages added, no versions changed).

npm audit	low	moderate	high	critical	total
before	5	18	38	2	63
after	3	11	25	0	39

Verification

• npx react-router routes --json before and after, normalized for child order: identical (66 entries). Route ids came out identical too, so useRouteLoaderData / matches lookups are unaffected.
• npx react-router build: passes
• npx vitest run: 24 files, 75 tests pass
• npx playwright test: 24 passed, 29 failed. main gives exactly the same result with the same 29 tests failing. The failures come from the local database being behind on Prisma migrations (e.g. column `game.tag_list` does not exist), not from this change.

🤖 Generated with Claude Code

[engleek]

Rebuilt on main after #249 merged, as one commit (force-pushed).

• Removed signup, forgot and reset/:token from the route config. Schema stage 1 (Schema cleanup, stage 1: remove unused parts, add org status and role #241, now on main) deleted those route files.
• react-router routes --json lists the same 63 routes as main, with the same ids and nesting.
• Lockfile: 1332 → 928 packages. No name@version that isn't already on main.
• npm audit: 34 → 8 (critical 1 → 0; 3 high, 4 moderate, 1 low left).
• Build ✅, vitest 137/137 ✅, Playwright 73/73 ✅ on a freshly migrated and seeded DB. The 29 earlier e2e failures came from a DB that was behind on migrations.