nisse-review: match repository patterns against Gitea's search

At bring-up, `dev/*` failed: listing an organization's repositories
(/orgs/dev/repos) needs the read:organization token scope, which the
reviewer's token doesn't have and shouldn't need. Patterns are now matched
against /repos/search, which needs only the repository scope and already
lists every repository the account can read. A pattern that matches
nothing is logged (access.no_match). owner_repositories goes.

A Gitea error at startup is now reported like a config error, not a
traceback.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01J5Utyfzw7gF7UhjRDEtjTk

nisse-review/tests/review_fakes.py

@@ -70,8 +70,7 @@ class FakeGitea:
     comments: list[tuple[str, int, str]] = field(default_factory=list)
     refuse_off_diff: bool = False
     down: bool = False
-    # Readable but not given (public): missing from /user/repos, as Gitea
-    # leaves a public repository's Read collaborators out of it.
+    # Readable but not given (public, no grant): missing from /user/repos.
     public: set[str] = field(default_factory=set)
 
     def _up(self) -> None:
@@ -89,13 +88,6 @@ class FakeGitea:
         self._up()
         return list(self.repos)
 
-    def owner_repositories(self, owner: str) -> list[str]:
-        self._up()
-        found = [r for r in self.repos if r.startswith(f"{owner}/")]
-        if not found:
-            raise GiteaNotFound(f"no owner {owner}")
-        return found
-
     def repository(self, repo: str) -> dict[str, Any]:
         if repo not in self.repos:
             raise GiteaNotFound(f"no repository {repo}")