fix: forge CLI pivot bugs against real tea/glab binaries

Fix critical bugs in the CLI transport layer that were masked by
idealized unit test mocks. All fixes verified against live binaries.

Server (gitea/client.js):
- C1: Remove --paginate flag (tea rejects it with exit 1)
- C2: Pass auth via -H 'Authorization: token' header instead of
  GITEA_SERVER_TOKEN env (tea ignores that env var)
- C3: Parse --include output from stderr (tea writes headers to
  stderr, not stdout)
- H2: Parse Link header for hasMore/pagination

Server (gitlab/client.js):
- C4: Remove /api/v4 prefix (glab adds it automatically; double
  prefix caused every call to 404)
- H2: Parse Link header for hasMore/pagination

Tests (both client.test.js):
- H1: Rewrite mocks to match real CLI behavior: headers on stderr
  for tea, no --paginate, auth via -H header, Link header parsing
- Add C3, C1, C4 specific regression tests

UI (GiteaSettings, GitLabSettings):
- U4: Replace return null loading state with animated skeleton
  (prevents blank flash)
- U2: Surface actual error message in connect failure toast
- U5: Add CLI transport hint below connect form
- U6 (GitLab): Add transport hint for unconnected state

UI (GiteaIssuePickerDialog, GitLabIssuePickerDialog):
- U3: Add retry button when error state is displayed

Live smoke tests passed:
- tea api -H 'Authorization: token WRONG' /user → 401
- tea api /repos/Vibing/openchamber/issues?state=open&limit=2 → 200
- glab api user with GITLAB_TOKEN=dummy → 401 (not 404)

packages/ui/src/components/session/GitLabIssuePickerDialog.tsx

@@ -545,7 +545,12 @@ export function GitLabIssuePickerDialog({
           ) : null}
 
           {error ? (
-            <div className="text-center text-muted-foreground py-8 break-words">{error}</div>
+            <div className="text-center text-muted-foreground py-8 space-y-2">
+              <div className="break-words">{error}</div>
+              <Button variant="outline" size="sm" onClick={refresh} disabled={isLoading}>
+                {t('session.gitlabIssuePicker.actions.refresh')}
+              </Button>
+            </div>
           ) : null}
 
           {directNumber && projectDirectory && gitlab && connected ? (