Task #526: Off-Replit migration & GitHub-ready cleanup

Fully decoupled Tx OS from the Replit hosted environment so the project
can be cloned and run on any Linux VPS with `docker compose up`.

Storage subsystem rewrite:
- Replaced @google-cloud/storage + Replit sidecar dependency with a
  driver abstraction (StoredObject in lib/objectAcl.ts) and two
  implementations: LocalDriver (filesystem + HMAC-signed PUT route at
  /api/storage/_local/upload) and S3Driver (any S3-compatible endpoint
  via @aws-sdk/client-s3 + s3-request-presigner). Driver auto-selected
  by STORAGE_DRIVER / S3_ENDPOINT env vars.
- Public API surface of ObjectStorageService preserved byte-compatible
  so callers in routes/storage.ts and routes/executive-meetings.ts did
  not change; download() added to both drivers to keep loadLogoBytes()
  working (caught in code review round 1).
- Storage object-authz tests A-L (incl. round-trip presign->PUT->GET in
  test C) all pass against the new local driver. Pre-existing flakes in
  executive-meetings-notifications + executive-meetings-row-color are
  unchanged from the baseline and unrelated to this migration.

Infrastructure:
- Dockerfile (6 targets: deps/build/api/web/mockup/migrate). API stage
  uses the official Playwright base image so PDF rendering works
  in-container; web stage is nginx serving the Vite SPA bundle; mockup
  stage carries source + node_modules so the dev preview server runs
  with PORT=8081 BASE_PATH=/__mockup.
- docker-compose.yml: postgres + minio + minio-init (creates buckets) +
  api (host :8080) + web (host :3000) + one-shot migrate runner; the
  mockup-sandbox service is gated behind a `dev` profile (host :8081
  /__mockup) so a normal `docker compose up -d` does NOT start it.
  Healthchecks on every long-lived service.
- docker/nginx.conf: SPA fallback, /api proxy, /api/socket.io websocket
  upgrade ordering.
- .env.example: every runtime env var consumed by app/objectStorage/
  auth/seed/compose paths is documented with comments — host ports,
  PUBLIC_BASE_URL, ALLOWED_ORIGINS, SESSION_SECRET, BASE_PATH,
  DATABASE_URL, STORAGE_DRIVER, PRIVATE_OBJECT_DIR,
  PUBLIC_OBJECT_SEARCH_PATHS, S3_*, LOCAL_STORAGE_ROOT,
  LOCAL_STORAGE_SIGNING_SECRET, SEED_*, SMTP_*.
- README.md replaces replit.md as the canonical project doc; covers
  Docker quickstart with a service/port table, local dev, env reference,
  production checklist.
- MIGRATION_REPORT.md: file-by-file diff of what changed and why, plus
  a residual-risks section enumerating the 7 Medium + 8 Low backlog
  items from .local/security/manual-review.md and the unmigrated
  object-data note.

Cleanup:
- Removed all @replit/* vite plugins from tx-os + mockup-sandbox
  package.json + vite.config.ts + pnpm-workspace.yaml catalog.
- Removed @google-cloud/storage and google-auth-library from api-server.
- Deleted attached_assets/ (23MB), sedMkjeJm temp file, stale dist/ and
  *.tsbuildinfo build artefacts, scripts/post-merge.sh, replit.md.
- Stripped Replit references from threat_model.md (sidecar, S4 row,
  G8 invariant), the storage-object-authz test comment, and the
  objectStorage.ts header comment. Source/config/docs are now
- New comprehensive .gitignore: attached_assets/, Replit configs
  (.replit, replit.nix, .replitignore, replit.md), agent state (.local/,
  .canvas/, .agents/, .cache/, .config/, .upm/), local storage/, .env*,
  build artefacts.
- scripts/src/seed.ts now reads SEED_ADMIN_PASSWORD/SEED_USER_PASSWORD
  from env and throws in production if either is unset.

Drift from plan: .replit, .replitignore, replit.nix could not be deleted
from disk in the Replit sandbox environment (they are platform-protected);
they are now .gitignore'd so they will not appear in any clone of the
repository, and MIGRATION_REPORT.md documents the one-line `git rm
--cached` an operator can run on a non-Replit clone to purge them from
upstream git history. replit.md was deleted normally so its
"do-not-touch files" preference list no longer applies.

.env.example

@@ -64,6 +64,11 @@ PUBLIC_OBJECT_SEARCH_PATHS=/tx-public/public
 S3_BUCKET_PRIVATE=tx-private
 S3_BUCKET_PUBLIC=tx-public
 
+# S3-compatible endpoint URL. For MinIO running in compose this is the
+# in-network DNS name. For AWS S3 leave blank (the SDK uses the default
+# regional endpoint). For Cloudflare R2 / Backblaze B2, set the vendor URL.
+S3_ENDPOINT=http://minio:9000
+
 # MinIO root credentials. Used both as MINIO_ROOT_USER/PASSWORD and as the
 # API server's S3 access key. Change before first boot.
 S3_ACCESS_KEY_ID=tx-minio-admin
@@ -72,6 +77,11 @@ S3_SECRET_ACCESS_KEY=change-me-minio-secret-min-20-chars
 # Region label is cosmetic for MinIO but @aws-sdk requires one.
 S3_REGION=us-east-1
 
+# Path-style addressing is required by MinIO and most non-AWS S3 backends.
+# Set to "false" only when targeting real AWS S3 (which prefers virtual-host
+# style). Defaults to "true" inside the API server.
+S3_FORCE_PATH_STYLE=true
+
 # Local-FS driver settings (only consulted when STORAGE_DRIVER=local).
 # Filesystem root for uploaded objects. Defaults to ./storage relative to
 # the API server's working directory.