fix(modules): three defects a real install exposed (phase 4, slice 1)

Standing the slice-2 screen up against a live server and installing the
published module-uo v0.3.0 through it found three things, none of which any
unit test in this repo could have caught. Two of them are older than this
phase.

1. The boot refresh nulled every install's provenance
--------------------------------------------------------
`installed_modules.source` and `.sha256` exist so the admin panel can say
where a module came from. They never survived a restart.

`lifecycle.boot()` re-records every scanned module with no source and no
sha256 -- correctly, because a scan finds a directory and never where it came
from -- and `upsert` assigned both columns unconditionally. So an install's
provenance lasted exactly until the restart that install asked for, and the
screen then described a module installed from a URL as "placed on the volume
by hand". Verified live: install, restart, provenance gone.

Nothing could have caught it before now. Phase 4 wrote the first non-null
value these columns had ever had, so lifecycle.js's comment asserting that
"recordInstalled leaves what it is not given" described an intention rather
than the statement below it -- and modules.model.test.js's fake reproduced
the defect faithfully, assigning unconditionally just like the SQL.

Fixed with COALESCE(VALUES(col), col): a value overwrites, a NULL leaves what
is there. The fake now matches, and two tests pin both directions -- a boot
refresh must not wipe it, and a re-install from a new URL must still replace
it, or the column would become write-once and an upgrade would for ever show
where the first version came from.

2. The restart killed the server on Windows instead of stopping it
------------------------------------------------------------------
The route called `process.kill(process.pid, 'SIGTERM')` to reach server.js's
graceful-shutdown handler. That works on Linux. **Windows has no POSIX
signals, and Node documents SIGTERM there as unconditional termination of the
target process** -- so on a Windows host the restart killed the server
outright: no module onShutdown, no listener close, no pool close, no log
flush. Observed exactly that: the process was gone and the shutdown handler
had logged nothing at all.

`process.on('SIGTERM', ...)` is an ordinary EventEmitter listener, so
`process.emit('SIGTERM')` reaches the same handler on every platform without
involving the OS. One shutdown path, still; it just gets there by an event.

Deployment is Linux containers and would never have shown this. Development
is not, and neither is the smoke that found it.

The test was worse than useless: it stubbed `process.kill` and asserted it
had been called with SIGTERM, which is precisely the call whose MEANING
differs by platform. It now waits for the SIGTERM EVENT -- what server.js is
actually subscribed to -- so a pass here means the handler would run.

3. `present()` did not publish the running version
--------------------------------------------------
An upgrade writes new files and a new row while the old code stays loaded, so
the row's version is a promise about the next boot rather than a description
of this one. Adds `liveVersion` from the loader beside `liveState`, so the
screen can tell the two apart instead of reporting the new version as running.

723 server tests (+2), manifest and OpenAPI both unchanged.

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

server/test/modules.model.test.js

@@ -38,7 +38,17 @@ modulesDb.getOne = async (id) => (rows.has(id) ? [rows.get(id)] : [])
 modulesDb.upsert = async ({ id, name, version, source, sha256 }) => {
   const existing = rows.get(id)
   if (existing) {
-    Object.assign(existing, { name, version, source: source ?? null, sha256: sha256 ?? null })
+    // COALESCE, matching the real statement: a value overwrites, a NULL leaves
+    // what is there. This fake used to assign unconditionally — faithfully
+    // reproducing the defect it was supposed to be able to catch, which is why
+    // the boot refresh nulling an install's provenance survived until a browser
+    // showed it.
+    Object.assign(existing, {
+      name,
+      version,
+      source: source ?? existing.source ?? null,
+      sha256: sha256 ?? existing.sha256 ?? null,
+    })
     return { affectedRows: 1 }
   }
   rows.set(id, {
@@ -116,6 +126,46 @@ test('a hand-placed module records with no provenance', async () => {
   assert.equal(mod.sha256, null)
 })
 
+test('the boot refresh does not wipe an install\'s provenance', async () => {
+  // The defect a browser found in Phase 4, and the reason the upsert COALESCEs.
+  //
+  // lifecycle.boot() re-records every scanned module with NO source and NO
+  // sha256, because a hand-placed directory genuinely has neither. That refresh
+  // used to write both columns as NULL, so an admin-panel install's provenance
+  // survived exactly until the restart the install asked for — and the screen
+  // then described a module installed from a URL as "placed on the volume by
+  // hand". Nothing could see it until Phase 4: no caller had ever passed a
+  // non-null value.
+  await modules.recordInstalled({
+    id: 'uo',
+    name: 'Ultima Online',
+    version: '1.0.0',
+    source: 'https://gitea.example/x/uo-1.0.0.json',
+    sha256: 'b'.repeat(64),
+  })
+
+  // What the next boot does.
+  const after = await modules.recordInstalled({ id: 'uo', name: 'Ultima Online', version: '1.0.0' })
+
+  assert.equal(after.source, 'https://gitea.example/x/uo-1.0.0.json')
+  assert.equal(after.sha256, 'b'.repeat(64))
+})
+
+test('a re-install from a new URL does replace the provenance', async () => {
+  // The other half: COALESCE must not make the columns write-once, or an upgrade
+  // would for ever show where the FIRST version came from.
+  await modules.recordInstalled({
+    id: 'uo', name: 'Ultima Online', version: '1.0.0', source: 'https://old/x.json', sha256: 'c'.repeat(64),
+  })
+  const after = await modules.recordInstalled({
+    id: 'uo', name: 'Ultima Online', version: '2.0.0', source: 'https://new/y.json', sha256: 'd'.repeat(64),
+  })
+
+  assert.equal(after.source, 'https://new/y.json')
+  assert.equal(after.sha256, 'd'.repeat(64))
+  assert.equal(after.version, '2.0.0')
+})
+
 test('recordInstalled refuses a manifest missing id, name or version', async () => {
   await assert.rejects(
     () => modules.recordInstalled({ id: 'uo', version: '1.0.0' }),