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-core/src/nisse_core/gitea.py

@@ -421,14 +421,6 @@ class GiteaClient:
                 return found
         raise GiteaError("too many repositories to list")
 
-    def owner_repositories(self, owner: str) -> list[str]:
-        """Every repository of an organization (or a user) this account can
-        read, as "owner/name"."""
-        try:
-            return self._paged_names(f"/orgs/{owner}/repos")
-        except GiteaNotFound:
-            return self._paged_names(f"/users/{owner}/repos")
-
     def visible_repositories(self) -> list[str]:
         """Every repository this account can read, public ones included."""
         return self._paged_names("/repos/search", key="data")