feat(uptimekuma): normalize names off Homepage, publish the status page, restore the widget

NAMES. Homepage already answers "what is this service called", so the monitor
name is now that name verbatim -- a second naming authority is how drift starts,
and an alert reading "[Uptime Kuma] Beszel hub is DOWN" sends you hunting for a
card that does not exist. Only two rows moved (Beszel hub -> Beszel, Dozzle hub
-> Dozzle); the " hub" suffixes were mine, not the services'.

The remaining mixed case is deliberate and is now documented as such. talk, vor
and task-board are lowercase on Homepage and in their own repos; title-casing
them here would make this board disagree with both. What actually looked messy
was scripts/kuma's own ASCII-ordinal sort, which buried every lowercase name
below every capitalised one. Fixed to case-insensitive.

⚠ RENAME SAFETY, which this pass needed and did not have. The seed keys on NAME,
so editing a name would have read as a brand-new monitor: added fresh, with the
old row orphaned, still checking, still alerting, and holding all the history.
`rename_from:` names the old row for one run. Verified: both renamed monitors
kept their IDs and all 67 heartbeats.

Added with it, an orphan warning for any row on the board the spec no longer
names -- because a forgotten monitor keeps paging. Its first cut diffed against
the PRE-EDIT snapshot and so cried wolf on its own successful renames; it
re-reads the board now. A warning that fires on its own correct work is worse
than no warning.

STATUS PAGE + WIDGET. The Homepage uptimekuma widget reads a PUBLISHED status
page (/api/status-page/<slug>), not the admin API -- which is why the widget
labels were deliberately absent from the rebuild: a dashboard widget pointed at
a 404 is the suspected mechanism behind both of Homepage's unkillable D-state
wedges, so shipping one on purpose would have been daft.

The page now exists at slug `nethealth` (the pre-rebuild slug, so old references
still resolve) and is DECLARED IN monitors.yaml, applied by `kuma seed`. Same
principle as the notification channel: a from-scratch rebuild restores the page,
the channel and the monitors together, and nothing the widget depends on lives
only in Kuma's database. Verified in a browser: "13 SITES UP / 0 SITES DOWN /
100% UPTIME" on the dashboard.

⚠ saveStatusPage calls imgDataUrl.startsWith() unconditionally, so passing null
throws and leaves the page CREATED BUT EMPTY -- which reads as success from
/api/status-page (200, correct title) while the group list is silently blank.
Pass "" instead. Commented at the call site.

stacks/uptimekuma/compose.yaml

@@ -66,13 +66,20 @@ services:
       - homepage.description=Service monitoring (fleet)
       - homepage.href=http://10.250.50.70:3001
       - homepage.siteMonitor=http://10.250.50.70:3001
-      # ⚠️ NO `homepage.widget.*` LABELS YET, deliberately. The widget needs a
-      #   published status-page slug; on a from-scratch install none exists, so
-      #   the widget would poll a 404 forever. That matters more than usual
-      #   here: homepage widgets pointed at dead targets are the suspected
-      #   mechanism behind BOTH of this dashboard's unkillable D-state wedges
-      #   (see incident_esh_docker_nfs_boot_race, 2026-06-03). Re-add the widget
-      #   labels only once the status page actually exists.
+      # The widget reads a PUBLISHED status page, not the admin API:
+      # /api/status-page/<slug> and /api/status-page/heartbeat/<slug>. These
+      # labels were deliberately absent from the 2026-09-21 rebuild until that
+      # page existed, because a dashboard widget pointed at a 404 is the
+      # suspected mechanism behind BOTH of Homepage's unkillable D-state wedges
+      # (incident_esh_docker_nfs_boot_race, 2026-06-03) -- shipping one on
+      # purpose would have been daft.
+      #
+      # The page is defined in monitors.yaml (`status_page:`) and applied by
+      # `scripts/kuma seed`, so a from-scratch rebuild restores the slug this
+      # points at. Slug `nethealth` is the one the pre-rebuild instance used.
+      - homepage.widget.type=uptimekuma
+      - homepage.widget.url=http://10.250.50.70:3001
+      - homepage.widget.slug=nethealth
     networks:
       - tnet