Import the wilm endpoint telemetry, PC Detail rework and backup overlay

Ports 37 of Benjamin Baker's commits from the wilm branch, mirrored from the
corporate GitHub at 7905917c. wilm rides the publication lineage and shares no
ancestor with wj, so this is a filtered tree patch rather than a merge:
94 files, and every path the publication export strips (docs/, tools/, mcp/,
CLAUDE.md, start-*.sh, .gitea/, the three excluded tests) is held back, because
a raw diff would delete each of them from this tree.

What comes across:

* Endpoint telemetry, phase 2. Physical disk health from two sources, NIC link
  state, boot type, Defender health, processor/memory/chassis inventory, the
  listening TCP set, mapped network drives and Windows Update history. Five
  additive migrations, 0012 through 0016, off the 0011 head.
* Mapped drives are collected by a probe running in the interactive user's
  session, because they do not exist in the agent's session 0. Two Windows
  sources can disagree about one drive and the worse status wins, so a
  half-broken share is never rendered as healthy.
* Windows events are reported once each, keyed on the channel's own record id,
  instead of being re-sent whenever a report overlapped the last one.
* PC Detail rework: Details cards flow, the hand-written Network card gives way
  to a full address history, Storage and disk health merge into one card with
  two sections, Operator Reports and Corporate Tools get their own tabs.
* An opt-in restic backup overlay with a third container, restore gated on the
  dump's own data revision rather than the code head, and backup/restore history.
* The agent's version is read from the binary's PE version rather than trusted
  from the csproj, and the Fleet view gains an Agent Version column.
* The enqueue route now asks caller_holds instead of the owner's permissions,
  which closes the scoped-token elevation on run_script, update_app and
  system_restart.

Held back deliberately:

* agent/installer/install-shopdbagent.ps1 stays deleted, as upstream deleted it.
  The installer that reaches a bay is generated by _install_script() in
  plugins/endpoints/api/siteagent.py; the standalone script had stopped being
  shipped and was collecting fixes no endpoint ever ran.
* The .gitignore hunk adding docs/*.md. Correct on the publication lineage,
  where docs/ becomes the wiki and its absence is how the gates detect a
  published checkout. Here it would silently ignore every new doc.
* Their deletions of docs/DEV-BUILD-TEST.md and docs/PLUGIN-HOOKS.md. Upstream
  those were stubs; here PLUGIN-HOOKS.md is the 31KB document CLAUDE.md points
  readers at.
* Five zero-byte files committed by an accidental `git add -A`, a run log from
  the author's own machine, and docs/notes/, which is working scratch that says
  so in its own header and belongs in devnotes/ on this side.

Carried with the import so it lands green: the 17 new routes are described in
docs/api-inventory.json with the spec and project map regenerated, and two new
frontend specs read fixtures through fileURLToPath(URL) which node rejects under
jsdom's own URL global.

Suite 2591 passed / 9 skipped; frontend 391 passed; naming, style and doc gates
clean.

Scope: product

tests/test_core/test_error_envelope.py

@@ -1,6 +1,6 @@
 """Every /api/ error answers in the documented envelope.
 
-docs/API-REFERENCE.md says an error is
+the API-REFERENCE wiki page says an error is
 {"status":"error","data":{"error":{"code","message"}},"meta":{...}}. Three
 statuses came straight from Werkzeug as HTML instead:
 

tests/test_core/test_pluginui_panel_groups.py

@@ -0,0 +1,44 @@
+"""The server-side panel group vocabulary must admit every group a plugin uses.
+
+`asset_panels()` resolves a panel's group BEFORE the client sees it, coercing
+any unrecognised value to 'details'. That makes ASSET_PANEL_GROUPS a third copy
+of the tab vocabulary, alongside RENDERED_GROUPS in PluginAssetPanels.vue and
+the tab list in PCDetail.vue. Phase 3 added 'serviceprocess' to the two
+frontend copies and missed this one, so both Service/Process panels were
+silently relabelled 'details' on the wire and the tab never appeared.
+
+The failure is invisible: no error, no log line, and the panels still render -
+just in the wrong tab, underneath the Details cards.
+"""
+from shopdb.core.api.pluginui import ASSET_PANEL_GROUPS
+from plugins.endpoints.plugin import EndpointsPlugin
+
+
+def test_every_group_the_endpoints_plugin_declares_survives_resolution():
+    declared = {
+        str(panel.get('group') or '').strip().lower()
+        for panel in EndpointsPlugin().get_asset_panels()
+    }
+    declared.discard('')
+    unknown = declared - set(ASSET_PANEL_GROUPS)
+    assert not unknown, (
+        f'panels declare {sorted(unknown)}, which the server rewrites to '
+        "'details' - the tab will not appear"
+    )
+
+
+def test_serviceprocess_is_admitted():
+    # Named explicitly: the generic test above would also pass if the
+    # serviceprocess panels were deleted outright.
+    assert 'serviceprocess' in ASSET_PANEL_GROUPS
+
+
+def test_reports_is_admitted():
+    # Same reasoning as serviceprocess above. Operator Reports was moved out of
+    # System Monitors into a tab of its own, which is the same three-copy
+    # change that Phase 3 got wrong.
+    assert 'reports' in ASSET_PANEL_GROUPS
+
+
+def test_details_remains_the_fallback():
+    assert ASSET_PANEL_GROUPS[0] == 'details'