fix(github-app): PAT fallback covers every mint failure; video/motion/x cleanups

mint_installation_token now wraps JWT build + HTTP + parsing so raw
httpx/jwt failures surface as GitHubAppError and the existing PAT
fallback catches them all (a GitHub outage no longer crashes git
operations for App-bound projects). The PEM is validated at
credential-set time instead of first mint, and the installation-token
cache is cleared when credentials are deleted. Also: the video
preview root resolves symlinks like its sibling route (frames under a
symlinked workspaces_root no longer false-404), the tracked dangling
motion/node_modules symlink is removed and the gitignore gains a
slash-less entry that actually matches symlinks, changelog caption
input strips GHSA refs like PR refs, and the edit-project dialog hides
the GitHub App section for auto-detected gitlab.com projects and warns
before a save that would clear both auth sources.

tests/unit/services/test_project_github_app_token.py

@@ -13,12 +13,28 @@ from __future__ import annotations
 from unittest.mock import AsyncMock, MagicMock, patch
 from uuid import uuid4
 
+import httpx
 import pytest
+from cryptography.hazmat.primitives import serialization
+from cryptography.hazmat.primitives.asymmetric import rsa
 from roboco.services.github_app_auth import GitHubAppAPIError
+from roboco.services.github_app_credentials import GitHubAppCredentialsData
 from roboco.services.project import ProjectService
 from roboco.utils.crypto import encrypt_token
 
 
+def _generate_rsa_pem() -> str:
+    private_key = rsa.generate_private_key(public_exponent=65537, key_size=2048)
+    return private_key.private_bytes(
+        encoding=serialization.Encoding.PEM,
+        format=serialization.PrivateFormat.PKCS8,
+        encryption_algorithm=serialization.NoEncryption(),
+    ).decode()
+
+
+_VALID_PEM = _generate_rsa_pem()
+
+
 def _project(*, installation_id: int | None, pat: str | None) -> MagicMock:
     p = MagicMock()
     p.id = uuid4()
@@ -99,6 +115,62 @@ async def test_mint_failure_falls_back_to_pat() -> None:
     assert token == "ghp_fallback"
 
 
+@pytest.mark.asyncio
+async def test_mint_network_error_falls_back_to_pat() -> None:
+    """A raw httpx failure inside the REAL mint path (not mocked away) must
+    still fall back to the PAT — github_app_auth wraps it as GitHubAppError
+    at its own chokepoint, which _resolve_token's existing except clause
+    already catches."""
+    svc = _svc_with_get(_project(installation_id=42, pat="ghp_fallback"))
+    fake_creds_svc = MagicMock()
+    fake_creds_svc.has_credentials = AsyncMock(return_value=True)
+    fake_creds_svc.get_decrypted = AsyncMock(
+        return_value=GitHubAppCredentialsData(app_id="1", private_key=_VALID_PEM)
+    )
+    client = MagicMock()
+    client.__aenter__ = AsyncMock(return_value=client)
+    client.__aexit__ = AsyncMock(return_value=False)
+    client.post = AsyncMock(side_effect=httpx.ConnectError("connection refused"))
+    with (
+        patch(
+            "roboco.services.project.get_github_app_credentials_service",
+            return_value=fake_creds_svc,
+        ),
+        patch(
+            "roboco.services.github_app_auth.get_github_app_credentials_service",
+            return_value=fake_creds_svc,
+        ),
+        patch("roboco.services.github_app_auth.httpx.AsyncClient", return_value=client),
+    ):
+        token = await svc.get_decrypted_token(uuid4())
+    assert token == "ghp_fallback"
+
+
+@pytest.mark.asyncio
+async def test_mint_corrupted_pem_falls_back_to_pat() -> None:
+    """A corrupted stored private key makes the REAL mint path's
+    ``jwt.encode`` raise ``InvalidKeyError`` before any network call — must
+    also fall back to the PAT."""
+    svc = _svc_with_get(_project(installation_id=42, pat="ghp_fallback"))
+    fake_creds_svc = MagicMock()
+    fake_creds_svc.has_credentials = AsyncMock(return_value=True)
+    fake_creds_svc.get_decrypted = AsyncMock(
+        return_value=GitHubAppCredentialsData(app_id="1", private_key="not-a-pem")
+    )
+    with (
+        patch(
+            "roboco.services.project.get_github_app_credentials_service",
+            return_value=fake_creds_svc,
+        ),
+        patch(
+            "roboco.services.github_app_auth.get_github_app_credentials_service",
+            return_value=fake_creds_svc,
+        ),
+    ):
+        token = await svc.get_decrypted_token(uuid4())
+    assert token == "ghp_fallback"
+
+
 @pytest.mark.asyncio
 async def test_mint_failure_with_no_pat_returns_none() -> None:
     svc = _svc_with_get(_project(installation_id=42, pat=None))