fix(skills): resolve project roots from session cwd

agent/skill_utils.py

@@ -419,20 +419,20 @@ _PROJECT_ROOT_MAX_DEPTH = 64  # walk-up bound for pathological cwds
 
 def find_project_root(start: Optional[Path] = None) -> Optional[Path]:
     """Nearest ancestor containing ``.git`` (dir or worktree file), or None.
-    Without *start*, the surface's ``TERMINAL_CWD`` wins over process cwd so
-    cron/API surfaces inherit an interactive trust decision by project identity.
-
-    When *start* is not given, the surface's working directory wins over the process cwd: ``TERMINAL_CWD``
-    is the same per-surface workdir the terminal tool and cron jobs use (a cron job sets it from its per-job
-    ``workdir`` without chdir'ing the scheduler process). This is what lets non-interactive surfaces inherit
-    a prior interactive trust decision by project identity — and a surface with no workdir in a trusted repo
-    simply resolves no project and loads nothing (#48975).
+    Without *start*, the surface's effective working directory wins over the process cwd — the same
+    ladder every other cwd consumer reads (``resolve_agent_cwd``: session-bound cwd, then the scope's
+    ``TERMINAL_CWD``, then the process cwd). The session cwd comes first because a multi-session host
+    (TUI/desktop gateway) pins each session's workspace there while its terminal scope resolves a
+    placeholder ``terminal.cwd`` to ``$HOME``; reading only the scope made every project skill invisible
+    on those surfaces (#114359). ``TERMINAL_CWD`` is the per-surface workdir the terminal tool and cron
+    jobs use (a cron job sets it from its per-job ``workdir`` without chdir'ing the scheduler process),
+    which lets non-interactive surfaces inherit a prior interactive trust decision by project identity —
+    and a surface with no workdir in a trusted repo simply resolves no project and loads nothing (#48975).
     """
     try:
         if start is None:
-            from agent.runtime_cwd import scope_terminal_cwd
-            env_cwd = scope_terminal_cwd()
-            start = Path(env_cwd) if env_cwd else Path.cwd()
+            from agent.runtime_cwd import resolve_agent_cwd
+            start = resolve_agent_cwd()
         cur = Path(start).resolve()
     except OSError:
         return None

tests/agent/test_project_skills.py

@@ -139,6 +139,25 @@ class TestNonInteractiveInheritance:
         assert su.find_project_root() == project_env["repo"].resolve()
         assert su.get_project_skills_dirs() != []
 
+    def test_session_cwd_beats_backend_launch_cwd(
+        self, project_env, monkeypatch, tmp_path
+    ):
+        """Desktop project skills follow the active session, not launch cwd."""
+        from gateway.session_context import clear_session_vars, set_session_vars
+
+        launcher = tmp_path / "desktop-launcher"
+        launcher.mkdir()
+        monkeypatch.chdir(launcher)
+        monkeypatch.setenv("TERMINAL_CWD", str(launcher))
+        _trust(project_env["config"], project_env["repo"])
+
+        tokens = set_session_vars(cwd=str(project_env["repo"]))
+        try:
+            assert su.find_project_root() == project_env["repo"].resolve()
+            assert su.get_project_skills_dirs() != []
+        finally:
+            clear_session_vars(tokens)
+
     def test_no_workdir_no_trust_inheritance(self, project_env, monkeypatch, tmp_path):
         # A surface running outside any repo (API server from home-like dir)
         # resolves no project even when OTHER repos are trusted.