fix: remove automatic third-party egress of user data + optional strict offline mode (OSM tiles, Scalar fonts, editor fonts, AI model downloads) (#422)

* fix: remove all automatic third-party egress (OSM tiles, Scalar fonts, editor Google Fonts, AI model download fallbacks)

Phone-home audit follow-up. The product no longer makes any automatic
third-party request; user-initiated click-outs stay, and production now
fails closed on missing AI models.

1. GPS leak via OSM tiles: the strip-metadata panel auto-loaded
   tile.openstreetmap.org tiles encoding the photo's GPS position. The
   Leaflet mini-map is gone; coordinates render as text plus an explicit
   View on map link (openstreetmap.org, opens on click only). Removed
   tile.openstreetmap.org from the CSP img-src, dropped the leaflet
   dependency, added the viewOnMap i18n key to all 21 locales.

2. Scalar docs fonts: /api/docs loaded Inter and JetBrains Mono from
   fonts.scalar.com. Scalar now renders with withDefaultFonts: false and
   both --scalar-font and --scalar-font-code pinned to system stacks;
   fonts.scalar.com removed from the docs CSP font-src. Verified by
   injecting GET /api/docs/: config carries withDefaultFonts false and
   the served page has no fonts.scalar.com reference.

3. Editor Google Fonts: the editor font picker built
   fonts.googleapis.com stylesheet URLs for 25 web fonts the served CSP
   already blocked. The remote loading path is deleted; the picker now
   offers system fonts only, with a SELF_HOSTED_FONTS seam (FontFace API,
   same origin) for bundling fonts later. Unknown families saved in old
   documents fall back to the browser default.

4. Python sidecar fails closed on model downloads: new
   packages/ai/python/offline_guard.py gates every runtime download
   fallback (inpaint, outpaint, restore, noise_removal, detect_faces,
   enhance_faces, face_landmarks, red_eye_removal, remove_bg, ocr,
   transcribe, upscale) behind SNAPOTTER_ALLOW_MODEL_DOWNLOAD=1 with an
   actionable error. Bundled models keep working untouched.

5. OCR and transcription library-internal downloads: unbundled PaddleOCR
   language and detection fallbacks now raise the guard error naming the
   language instead of resolving models over the network; faster-whisper
   gets local_files_only when downloads are off.

6. GFPGAN and CodeFormer cwd-relative weights: facexlib and
   codeformer-pip resolve helper weights relative to the process cwd and
   fetch them from GitHub when absent. They are now symlinked from the
   installed bundle files under MODELS_PATH/gfpgan/facelib before the
   libraries load, failing closed when unresolvable.

Defense in depth: HF_HUB_OFFLINE=1 and TRANSFORMERS_OFFLINE=1 are set in
the runtime image and in the sidecar spawn env; install_feature.py lifts
them for user-initiated bundle installs and restores them afterwards
(it can run in-process inside the dispatcher). SNAPOTTER_ALLOW_MODEL_DOWNLOAD
is documented in .env.example, default off.

Validation: typecheck 9/9 workspaces, Biome clean on touched files,
5178 unit tests pass, py_compile on all touched scripts, guard behavior
exercised in both dispatcher exec and per-request import modes, zero
remaining runtime references to the three hosts. Docker build and live
AI inference need post-merge verification on the GPU host.

Claude-Session: https://claude.ai/code/session_01XGB4pGvTvb7sUX4JN745U7

* fix: allow AI model downloads by default, make strict offline mode opt-in

Product call: ease of use first. The download gating from the previous
commit inverts its default: runtime model fetches (public model weights
only, never user data) are allowed out of the box so AI tools self-heal,
and SNAPOTTER_ALLOW_MODEL_DOWNLOAD=0 becomes the explicit strict offline
mode for airgapped deployments, where every fallback raises the
actionable error instead of fetching.

Changes: offline_guard blocks only on an explicit 0/false; the
unconditional HF_HUB_OFFLINE/TRANSFORMERS_OFFLINE image ENV is removed
and bridge.ts sets those flags for the sidecar only in strict mode;
.env.example documents the new default; install_feature's lift/restore
stays. All bundled-path preferences, pre-existence checks, and symlink
pre-placement remain, so installed bundles never trigger a download.
The OSM, Scalar font, and editor font fixes are unchanged.

Validation rerun: typecheck 9/9, Biome clean on touched files, 5178
unit tests pass, py_compile on touched scripts, guard behavior verified
for unset/1 (allowed) and 0/false (blocked with the new message).

Claude-Session: https://claude.ai/code/session_01XGB4pGvTvb7sUX4JN745U7

packages/ai/python/install_feature.py

@@ -357,6 +357,29 @@ def write_installed_atomic(ai_dir: str, data: dict) -> None:
 # -- Main --
 
 def main() -> None:
+    """Run the install with runtime-download restrictions lifted.
+
+    In strict offline mode (SNAPOTTER_ALLOW_MODEL_DOWNLOAD=0) the sidecar
+    runs with HF_HUB_OFFLINE/TRANSFORMERS_OFFLINE=1; a bundle install is an
+    explicitly user-initiated download, so those flags are lifted here
+    regardless. The previous values are restored in the finally block because
+    this script can run in-process inside the long-lived dispatcher, where
+    os.environ changes would otherwise leak into every later request.
+    """
+    saved = {key: os.environ.get(key) for key in ("HF_HUB_OFFLINE", "TRANSFORMERS_OFFLINE")}
+    os.environ["HF_HUB_OFFLINE"] = "0"
+    os.environ["TRANSFORMERS_OFFLINE"] = "0"
+    try:
+        _install()
+    finally:
+        for key, value in saved.items():
+            if value is None:
+                os.environ.pop(key, None)
+            else:
+                os.environ[key] = value
+
+
+def _install() -> None:
     if len(sys.argv) < 4:
         fail(
             f"Usage: {sys.argv[0]} <bundleId> <manifestPath> <modelsDir>\n"