fix(web): uniqueItems saves, /health count, Vegas order wipe; one list-repair helper (#638)

* fix(web): drop repeats from uniqueItems lists before validating a plugin save

dedup_unique_arrays lost its only caller in #330, so submitting a value a
uniqueItems list already holds (a stock symbol saved once and posted again)
failed the whole save with a validation error. _prepare_plugin_config_for_save
runs it again just before validation, which covers both POST /plugins/config
and plugin sections posted to /config/main.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(web): /health counts the discovered plugins and logs the checks it fails

The plugin check counted plugin_manager.get_available_plugins(), which
PluginManager does not have, behind a hasattr guard that made plugin_count 0
on every device. It now counts the discovered manifests, discovering first
when nothing has been scanned yet.

The config, plugin and hardware checks answered "see logs for details"
without logging anything. Each now logs a warning with the traceback.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(web): store refresh no longer claims a commit-metadata refresh

POST /plugins/store/refresh read fetch_commit_info (or fetch_latest_versions)
only to append "(with refreshed commit metadata from GitHub)" to its message.
It never fetched any: the route re-downloads the registry and nothing else.
search_plugins takes the flag, but it reads commit info through its cache,
so passing it on would not refresh anything either. The flag is ignored now
and the message says what happened.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(web): refuse a malformed Vegas plugin order instead of clearing it

A vegas_plugin_order or vegas_excluded_plugins value that was not JSON, or
not a list, was stored as [] and the save answered 200, so a bad value wiped
the saved order or exclusions. Both now answer 400 and save nothing, the way
plugin_rotation_order already did; the three share one parser. A list that
holds anything but plugin-id strings is refused as well.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(web): per-plugin health and metrics read the display service's latest

GET /plugins/health/<id> and /plugins/metrics/<id> called get_health_summary
and get_metrics_summary without force_reload, so they answered with whatever
the web process read first and kept in memory, while the display service kept
writing newer state. They now pass force_reload=True, as the list routes do.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(web): plugin config reset saves through the shared atomic save

POST /plugins/config/reset called config_manager.save_config directly, so it
took no backup, and a failed write escaped as an unhandled exception. It then
handed on_config_change the raw stored section, not the prepared config a
loaded plugin runs with. It now saves through _save_config_atomic with a
backup, answers CONFIG_SAVE_FAILED when that fails, and notifies with
_prepared_plugin_config, as POST /plugins/config does.

POST /plugins/toggle carried its own copy of _save_config_atomic's
save_config_atomic-or-save_config fallback; it calls the shared helper now.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(web): one reading and one "unavailable" for each system metric

system_metrics.collect_system_metrics() promised None for a metric it could
not read, but returned cpu_temp as 0 off a Pi, and the whole no-psutil
fallback as zeros. GET /system/status measured the same numbers a second time
with its own code, and answered None there. Now both come from
collect_system_metrics(), and "unavailable" is None everywhere.

/system/status keeps its 0.1s CPU sample and its 10s cache, and gains
nothing it did not already send. Two differences: without psutil it answers
200 with null metrics instead of 503, and a disk it cannot stat is null
instead of a 500.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* fix(web): /display/current sends the snapshot as-is and logs a failed read

GET /display/current PIL-decoded the preview snapshot and re-encoded it before
base64-ing it, spending CPU on the Pi to send the same picture, and dropped
any failure with `except Exception: pass`. The /stream/display SSE stream
already passed the PNG's bytes straight through.

Both now read through web_interface/display_preview.py and answer with the
same payload. A missing snapshot is still a null image; any other read
failure is logged as a warning. /health reads the snapshot path from the same
module.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* refactor(web): one helper puts a submitted plugin config's lists back

The plugin-config save turned position-keyed dicts ({"0": ..., "1": ...})
back into lists in five copies: four in the form path's
fix_array_structures (whose prefix branches never ran, since no caller
passed one), and _fix_json_arrays on the JSON path. It then force-fixed
the news plugin's feeds.custom_feeds by name, in case the generic pass had
missed it. src/web_interface/config_arrays.coerce_array_shapes now does it
for both paths, custom_feeds included. ensure_array_defaults duplicated
_fix_none_arrays and is gone.

In the same function: the union-type re-checks that the null handling
above them made unreachable, the "(temporary)" random_seed debug log, and
a commented-out log line are removed. A failed validation is logged once
as a warning, not four ERROR lines and a WARNING.

Element types are left to normalize_config_values, which already converted
them for both paths. One difference: the form path no longer adds an empty
{} for a nested object the post left out that has no defaults.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* refactor(web): import at module top and log through the module logger

The web_interface.cache imports in config.py and fonts.py were wrapped in
`except ImportError` fallbacks. It is an in-repo module that imports nothing
from the project, so it cannot fail to import; it is imported once at module
top, as system.py now does. cache.py's docstring said blueprints import it
lazily "to avoid circular imports"; it now says why that is unnecessary.

Five logging.error calls in the dim-schedule GET and three logging.warning
calls in plugins.py went to the root logger; they use the module logger.
Function-local re-imports of json, os, shutil, logging and Path, all
already imported by the module, are gone. The `import os` inside two except
blocks of save_plugin_config also made os a local name for the whole function.

execute_plugin_action's step-1 handler gets a comment saying why it stays:
it looks like a copy of the blueprint handler, but without it a
TimeoutExpired from the plugin's script would reach the route's own
`except subprocess.TimeoutExpired` and be answered as a 408.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* refactor(web): app.py loses dead CSRF and reconciliation state, comments fixed

- csrf was always None, so `if csrf: csrf.exempt(...)` never ran, and its
  note that the api_v3 blueprint "is exempted above" named an exemption that
  does not exist. Both are gone; the reason there is no CSRF protection stays,
  shortened.
- The SSE rate-limit comment called the default "tight" at 20 per minute. The
  default is 1000 per minute and the streams' 200 is the tighter one; the
  comment now says so. The limits are unchanged.
- _reconciliation_done was written and never read. The docstring that
  explains why reconciliation runs once keeps its reason, in the present
  tense.
- Removed: a dangling "import cache functions" comment with no import under
  it, a "security check ... within project_root" label on an existence check,
  the "(simplified version)" narration, and the note that no redirect route is
  needed. The preview loop's sleep comment no longer mentions a PIL encode
  that the loop does not do.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* docs(web): api_v3 comments name the package __init__, not a _common module

Every route module's docstring said the shared blueprint comes "from
._common", a module the package split never created; they name the
package __init__. The PROJECT_ROOT comment described the path from
_common.py; it now describes this package and keeps the incident it
guards against. The "(corrected) in this commit" note in
resolve_pull_command and the /health comment the split's mechanical
time -> _pkg.time rewrite garbled ("Stamp the start _pkg.time") read
correctly again.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* refactor(web): drop hasattr checks for attributes PluginManager always has

PluginManager.__init__ sets health_tracker and resource_monitor (to None
until they are configured), so the seven
hasattr(api_v3.plugin_manager, ...) guards in the health, metrics and limits
routes were always true. The falsy checks that do the work stay.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* refactor(web): pages_v3 dispatches partials from a dict with one error handler

load_partial chose a loader through a fourteen-branch if/elif, and thirteen
of the loaders then wrapped themselves in the same try/except, logging
"Error loading partial" without saying which. The route now looks the name up
in _PARTIAL_LOADERS and has the one handler, which logs the partial's name.
The loaders just render. _load_tools_partial keeps its own messages. The
search index's _partial_html already catches a loader that raises.

serve_plugin_web_ui repeated _plugin_dir_for inline (containment plus the
ledmatrix- prefix fallback); it calls it now. Also removed: the unused
markupsafe.escape import, function-local json/Path re-imports, and unused
exception bindings.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* refactor(web): remove unused imports, locals and a try that cannot fail

- get_error_aggregator was imported by the api_v3 package and used by no
  one; seven names config.py imported, and Path in misc.py and logging in
  plugins.py, likewise.
- branch_info in install_plugin was built and never logged; test_config in
  /health was bound and never read (the load_config call is the check).
- An f-string with no placeholders in the asset upload route.
- _installed_plugin_ids wrapped list(manifests.keys()) in try/except;
  _discovered_plugin_manifests always returns a dict.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* refactor(web): start.py logs its startup lines and drops unreachable branches

The startup banner went to stdout with print(); it goes through a logger
now, which the app import has already configured, so it reaches the journal
with a level and timestamp like every other line. The "no addresses" branch
is gone: get_local_ips() always returns at least "localhost".

The except around app.run re-raised "only if it's not a client
disconnection error" from inside the branch that had just established it
was one, so that raise could not run. It is one check now, on a named
tuple of the errnos, which the werkzeug log filter uses too. The comment
on threaded=True counts three SSE endpoints, which is how many there are.
Trailing whitespace is stripped.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* refactor(web): save_main_config names its General fields once

The General tab's field names were listed twice, once to detect a General
form post and again, with four more, to keep the remaining-keys merge from
storing them as top-level keys. GENERAL_FIELDS and _MAPPED_TOP_LEVEL_FIELDS
hold them now, and the four per-section skip checks are one set.

The comment on that merge said plugin configs are handled "here too", and
"(including plugin keys)". Plugin sections are handled and removed from the
body before it runs; the comment says so.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* refactor(web): plugin directories come from the plugin manager only

Six lookups fell back to PROJECT_ROOT/plugins/<id> when there was no plugin
manager: GET /plugins/config's of-the-day data, POST /plugins/action, the
plugin static-file route, the calendar credentials upload and the calendar
OAuth routes. The loader never scans plugins/ (PluginManager.discover_plugins
reads only the configured directory, plugin-repos by default), so what they
found there was a plugin that never runs. _plugin_directory() asks the
manager and answers None without one, which each route already reports as
"not found".

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

* docs(changelog): web-backend

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

test/test_pages_v3_partials.py

@@ -0,0 +1,65 @@
+"""/partials/<name> dispatch and the plugin web_ui page's directory lookup."""
+
+import logging
+import sys
+from pathlib import Path
+from unittest.mock import MagicMock
+
+import pytest
+from flask import Flask
+
+sys.path.insert(0, str(Path(__file__).parent.parent))
+
+from web_interface.blueprints import pages_v3 as module  # noqa: E402
+
+
+@pytest.fixture
+def client(tmp_path, monkeypatch):
+    plugin_manager = MagicMock()
+    plugin_manager.plugins_dir = tmp_path
+    monkeypatch.setattr(module.pages_v3, "plugin_manager", plugin_manager, raising=False)
+    monkeypatch.setattr(module.pages_v3, "config_manager",
+                        MagicMock(load_config=lambda: {}), raising=False)
+    app = Flask(__name__, template_folder=str(
+        Path(module.__file__).resolve().parents[1] / "templates"))
+    app.register_blueprint(module.pages_v3)
+    return app.test_client()
+
+
+def test_every_tab_the_old_if_chain_served_is_still_served():
+    assert set(module._PARTIAL_LOADERS) == {
+        "overview", "general", "display", "durations", "schedule", "plugins",
+        "fonts", "logs", "raw-json", "backup-restore", "wifi", "cache",
+        "operation-history", "tools",
+    }
+
+
+def test_an_unknown_partial_is_a_404(client):
+    response = client.get("/partials/nope")
+    assert response.status_code == 404
+
+
+def test_a_failing_loader_is_one_500_that_names_the_partial(client, monkeypatch, caplog):
+    def boom():
+        raise RuntimeError("template exploded")
+    monkeypatch.setitem(module._PARTIAL_LOADERS, "logs", boom)
+
+    with caplog.at_level(logging.ERROR):
+        response = client.get("/partials/logs")
+
+    assert response.status_code == 500
+    assert response.get_data(as_text=True) == "Error loading partial"
+    errors = [r for r in caplog.records if r.levelno >= logging.ERROR]
+    assert len(errors) == 1
+    assert errors[0].getMessage() == "Error loading partial logs"
+
+
+def test_web_ui_page_uses_the_ledmatrix_prefix_fallback(client, tmp_path):
+    web_ui = tmp_path / "ledmatrix-radar" / "web_ui"
+    web_ui.mkdir(parents=True)
+    (web_ui / "panel.html").write_text("<p>radar panel</p>", encoding="utf-8")
+
+    response = client.get("/plugin-ui/radar/web-ui/panel.html")
+
+    assert response.status_code == 200
+    assert "radar panel" in response.get_data(as_text=True)