fix(release): fail closed on dashboard parse errors

tools/release/govoplan_release/model.py

@@ -111,6 +111,17 @@ class MigrationTrackSnapshot:
     error: str | None = None
 
 
+@dataclass(frozen=True, slots=True)
+class DashboardCollectionError:
+    """Bounded, actionable failure from read-only dashboard collection."""
+
+    code: str
+    message: str
+    remediation: str
+    repo: str | None = None
+    source: str | None = None
+
+
 @dataclass(frozen=True, slots=True)
 class DashboardSummary:
     repository_count: int
@@ -139,6 +150,7 @@ class ReleaseDashboard:
     catalog: CatalogSnapshot
     migrations: tuple[MigrationTrackSnapshot, ...] = ()
     contracts: tuple[ModuleContractSnapshot, ...] = ()
+    collection_errors: tuple[DashboardCollectionError, ...] = ()
 
 
 @dataclass(frozen=True, slots=True)