feat(cli): install SessionStart hook chaining self-upgrade then pull

Single hook entry: 'agnes self-upgrade --quiet ... || true; agnes pull
--quiet ... || true'. Shell semicolon guarantees ordering across every
Claude Code version (no reliance on undocumented multi-hook execution
semantics); each segment's || true preserves the original property
that an upgrade failure does not abort the pull.

cli/lib/hooks.py

@@ -24,7 +24,7 @@ from pathlib import Path
 # Substrings that identify "our" hook commands. Includes legacy `da sync`
 # so a workspace bootstrapped by an older CLI gets cleanly upgraded on the
 # next `agnes init` run.
-_OUR_COMMAND_MARKERS = ("agnes pull", "agnes push", "da sync")
+_OUR_COMMAND_MARKERS = ("agnes self-upgrade", "agnes pull", "agnes push", "da sync")
 
 
 def install_claude_hooks(workspace: Path) -> None:
@@ -60,7 +60,11 @@ def install_claude_hooks(workspace: Path) -> None:
                 existing.remove(entry)
         existing.append({"hooks": [{"type": "command", "command": command}]})
 
-    _replace_or_add("SessionStart", "agnes pull --quiet 2>/dev/null || true")
+    _replace_or_add(
+        "SessionStart",
+        "agnes self-upgrade --quiet 2>/dev/null || true; "
+        "agnes pull --quiet 2>/dev/null || true",
+    )
     _replace_or_add("SessionEnd", "agnes push --quiet 2>/dev/null || true")
 
     settings_path.write_text(json.dumps(cfg, indent=2) + "\n", encoding="utf-8")

tests/test_lib_hooks.py

@@ -14,9 +14,9 @@ def _read_settings(workspace: Path) -> dict:
 def test_install_creates_settings_file(tmp_path):
     install_claude_hooks(tmp_path)
     cfg = _read_settings(tmp_path)
-    assert cfg["hooks"]["SessionStart"]
-    assert "agnes pull --quiet" in cfg["hooks"]["SessionStart"][0]["hooks"][0]["command"]
-    assert cfg["hooks"]["SessionEnd"]
+    cmd = cfg["hooks"]["SessionStart"][0]["hooks"][0]["command"]
+    assert "agnes self-upgrade --quiet" in cmd
+    assert "agnes pull --quiet" in cmd
     assert "agnes push --quiet" in cfg["hooks"]["SessionEnd"][0]["hooks"][0]["command"]
 
 
@@ -74,3 +74,25 @@ def test_install_handles_invalid_json(tmp_path, capsys):
     install_claude_hooks(tmp_path)
     captured = capsys.readouterr()
     assert "not valid JSON" in captured.err or "warning" in captured.err.lower()
+
+
+def test_install_chains_self_upgrade_then_pull_in_one_entry(tmp_path):
+    install_claude_hooks(tmp_path)
+    cfg = _read_settings(tmp_path)
+    session_start = cfg["hooks"]["SessionStart"]
+    assert len(session_start) == 1, session_start
+    cmd = session_start[0]["hooks"][0]["command"]
+    assert "agnes self-upgrade --quiet" in cmd
+    assert "agnes pull --quiet" in cmd
+    # Order is encoded in the shell — self-upgrade must appear first
+    assert cmd.index("agnes self-upgrade") < cmd.index("agnes pull")
+    # Both segments carry || true so neither failure aborts the line
+    assert cmd.count("|| true") >= 2
+
+
+def test_install_idempotent_chained_entry(tmp_path):
+    install_claude_hooks(tmp_path)
+    install_claude_hooks(tmp_path)
+    cfg = _read_settings(tmp_path)
+    assert len(cfg["hooks"]["SessionStart"]) == 1
+    assert len(cfg["hooks"]["SessionEnd"]) == 1