v1.45.2: hardening from the v1.45.1 review — R4-1, R4-2

R4-1: collecting superseded plan files runs after the configuration is already
durable, but an error listing the directory propagated out of config/set. The
client saw a failure for a revision the server had committed, and its retry
came back as a conflict. collect_plans now reports 0 instead of raising, and
config/set logs and proceeds — the event fires, the revision is returned.

R4-2: the pending set was cleared when a batch went out, not when it came back,
so every render during an in-flight content/sign queued another request: six
calls where one was needed, and unbounded on a socket that is slow rather than
busy. Queued and in-flight are separate states now; a failure backs off (2 s
doubling to 60 s) instead of retrying on the next frame; an in-flight entry
expires after 15 s so a promise that never settles cannot wedge retries; a late
answer after dispose() no longer renders.

Tests: test/signing.test.mjs — eight cases with hand-settled promises, verified
against a v1.45.1 checkout where four of them fail (2 sign calls instead of 1,
no backoff, a late answer rendering after teardown). Backend: a broken
collector still yields a successful save whose revision the next CAS accepts.
Pure collector: a disappearing directory returns 0.
Docs: CHANGELOG.md + CHANGELOG.ru.md + ARCHITECTURE.md + TESTING.md + STATUS.md.

custom_components/houseplan/plans.py

@@ -63,14 +63,23 @@ def collect_plans(
       * any other unreferenced plan file is a rejected or abandoned upload, and
         is removed only once PLAN_ORPHAN_TTL_S has passed: a fresh one may
         belong to a transaction that has not committed yet.
+
+    Never raises: the configuration is already stored by the time this runs, so
+    a file-system problem must not turn a durable commit into a failed call.
     """
-    if not plans_dir.is_dir():
-        return 0
     new_refs = plan_refs(new_cfg)
     old_refs = plan_refs(old_cfg)
     cutoff = (time.time() if now is None else now) - PLAN_ORPHAN_TTL_S
     removed = 0
-    for item in sorted(plans_dir.iterdir()):
+    try:
+        items = sorted(plans_dir.iterdir()) if plans_dir.is_dir() else []
+    except OSError as err:
+        # The directory can vanish or turn unreadable between the check and the
+        # walk. This is housekeeping running behind a commit that is already
+        # durable, so it reports "nothing collected" instead of failing (R4-1).
+        _LOGGER.warning("House Plan: could not list %s: %s", plans_dir, err)
+        return 0
+    for item in items:
         if not item.is_file() or item.name in new_refs or not is_plan_file(item.name):
             continue
         superseded = item.name in old_refs