fix(s6): make profile gateway log parent writable (#46291)

* fix(gateway): chown logs/gateways parent so late-added profiles can log

The per-profile log service script created $HERMES_HOME/logs/gateways/
via 'mkdir -p' but only chowned the leaf logs/gateways/<profile>. When
the first log service boots in root context, the gateways/ parent stays
root:root; every profile registered later runs its log service as the
dropped hermes user, 'mkdir -p' fails with EACCES, and s6-log enters a
sub-second fatal crash-loop flooding the container log. The stage2
recursive heal does not catch it either: it is gated on needs_chown,
which is false when the top-level $HERMES_HOME is already hermes-owned.

Two complementary fixes:

- service_manager._render_log_run: chown the gateways/ parent
  (non-recursively) before the leaf chown. Runs on every root-context
  boot, so it also heals volumes already poisoned by older images.
- docker/stage2-hook.sh: seed logs/gateways in the as_hermes mkdir -p
  block; cont-init runs before any service starts, so the parent
  already exists hermes-owned when the first log/run does 'mkdir -p'.

The needs_chown repair loop needs no twin entry: it already chowns
logs/ recursively, which covers logs/gateways.

Fixes #45258

* chore(release): map salvaged contributor

---------

Co-authored-by: tangtaizhong666 <tangtaizhong792@gmail.com>

tests/tools/test_stage2_hook_log_dir_seed.py

@@ -0,0 +1,60 @@
+"""Contract test: the s6-overlay stage2 hook seeds $HERMES_HOME/logs/gateways
+as the hermes user.
+
+Regression guard for #45258: the per-profile gateway log service
+(`gateway-<profile>/log/run`) creates `logs/gateways/` via `mkdir -p` but only
+chowns the leaf `logs/gateways/<profile>`. If the first log service to boot
+runs in root context, the `gateways/` parent is created root-owned and stays
+that way; every profile registered later runs its log service as the dropped
+hermes user and s6-log crash-loops on `mkdir: Permission denied`.
+
+Seeding `logs/gateways` in stage2 (cont-init runs before any service starts)
+guarantees the parent already exists hermes-owned by the time the first
+log/run executes its `mkdir -p`.
+"""
+from __future__ import annotations
+
+import re
+from pathlib import Path
+
+import pytest
+
+REPO_ROOT = Path(__file__).resolve().parents[2]
+STAGE2_HOOK = REPO_ROOT / "docker" / "stage2-hook.sh"
+
+
+@pytest.fixture(scope="module")
+def stage2_text() -> str:
+    if not STAGE2_HOOK.exists():
+        pytest.skip("docker/stage2-hook.sh not present in this checkout")
+    return STAGE2_HOOK.read_text()
+
+
+def _seed_mkdir_block(text: str) -> str:
+    """Extract the `as_hermes mkdir -p \\ ...` seed block."""
+    m = re.search(r"as_hermes mkdir -p \\\n(?:[^\n]*\\\n)*[^\n]*\n", text)
+    assert m, "stage2-hook.sh must contain the as_hermes mkdir -p seed block"
+    return m.group(0)
+
+
+def test_logs_gateways_is_seeded(stage2_text: str) -> None:
+    block = _seed_mkdir_block(stage2_text)
+    assert '"$HERMES_HOME/logs/gateways"' in block, (
+        "logs/gateways must be seeded hermes-owned in stage2 so profiles "
+        "added after first boot can create their log dirs (#45258)"
+    )
+    # The parent must also be seeded so mkdir -p inside the block never
+    # creates logs/ implicitly with surprising ownership.
+    assert '"$HERMES_HOME/logs"' in block
+
+
+def test_logs_subtree_is_healed_when_chown_needed(stage2_text: str) -> None:
+    """The needs_chown repair loop must cover the logs subtree recursively —
+    that is what makes the seed entry above sufficient (no separate
+    logs/gateways loop entry needed)."""
+    m = re.search(r"for sub in ([^;]*); do", stage2_text)
+    assert m, "stage2-hook.sh must contain the needs_chown subdir repair loop"
+    assert "logs" in m.group(1).split(), (
+        "the needs_chown loop must recursively chown logs/ — it covers "
+        "logs/gateways, so the seed list does not need a loop twin"
+    )