fix(git): review follow-ups for #1357 (S1, S2, indent)

S1: get_gitea_login_for_repo_override() now distinguishes "tea is not
installed" from "no tea login named X exists", mirroring the host path.
The old message diagnosed a cause that was never checked and pointed at
seat-logins.sh, which cannot run without tea. Branch 6 in
test-gitea-login-resolution.sh pins it (tea removed from PATH); reverting
the fix fails that branch.

S2: issue-list/pr-list/pr-view override-path error now points at the
lines above for the cause instead of suggesting a default tea login.

verify-release.mjs: indent of the #1356 test line fixed (cosmetic).

packages/mosaic/framework/tools/git/detect-platform.sh

@@ -468,6 +468,14 @@ get_gitea_login_for_repo_override() {
                 echo "$canon"
                 return 0
             fi
+            # Same split as the host path above (#1357 S1): a missing tea binary
+            # is not a missing login, and the "create it with" advice cannot be
+            # followed without tea.
+            if ! command -v tea >/dev/null 2>&1; then
+                echo "Error: git identity '$ident' (via $ident_src) requested for owner '${owner%%/*}', but tea is not installed," >&2
+                echo "       so no login can be resolved. Refusing to guess an identity." >&2
+                return 1
+            fi
             echo "Error: git identity '$ident' (via $ident_src) has no tea login '$canon' for owner '${owner%%/*}'." >&2
             echo "       Create it with:  ~/.config/mosaic/tools/fleet/seat-logins.sh --apply --seat $ident" >&2
             return 1