feat(storage): move desktop SQLite ownership into a storage utility process

Main no longer opens desktop business SQLite. A single utility-process
storage owner holds the Assistant, Knowledge, attachment, document-result,
remote-binding and native model-ledger databases and runs whole domain
transactions; Main and Runtime callers use explicit async domain operations.

- Remove the Main readWithFallback path and the supervision worker's
  separate business write connection; manifests are scanned read-only and
  committed by the sole writer.
- Remote events are ACKed only after commit; process loss reports
  unconfirmed writes instead of replaying them.
- Use native utilityProcess messaging with one in-flight bound (32) and
  ordered waiting instead of capacity rejection and retries.
- Start the storage process before the window so startup overlaps.
- Keep short tool output in memory and store full output once in owned
  storage; paging, branching, restart and deletion reuse that copy.
- Put required runtime launch files under goodbuddy-prefixed owned temp
  directories and reclaim confirmed stale ones; stop writing duplicate
  parsed.md.
- Add lint guards for SQLite ownership and architecture, concurrency
  acceptance fixtures, and maintenance/architecture documentation.

Validation: typecheck and lint pass. Alternating baseline (edf019aa) vs
candidate runs show no regression on single-session, C01, C02, C04 and a
5-minute C06; Main p99 drops from ~21 ms to ~16.7 ms under concurrency.
Fresh portable copy (1.75M events) upgrade content unchanged; real-model
output paging passes with 4 external requests. Full npm test runs had
1-9 different timing-sensitive failures per run that pass when rerun.
Not covered: C03 review publication, C07 source body, app-level C05.

tests/support/app-perf-driver.mjs

@@ -264,6 +264,7 @@ async function measure(id, description, body) {
       }
     },
     processes: {
+      pids: app.getAppMetrics().map(metric => ({ pid: metric.pid, type: metric.type, cpu: metric.cpu.percentCPUUsage, workingSetMB: metric.memory.workingSetSize / 1024 })),
       cpu: Object.fromEntries(Object.entries(processes).map(([type, value]) => [type, value.cpu])),
       workingSetMB: Object.fromEntries(Object.entries(processes).map(([type, value]) => [type, Math.round(value.workingSetMB)]))
     },
@@ -511,6 +512,15 @@ try {
   await applyCpuThrottle()
   await sleep(1_500)
 
+  if (process.env.GB_PERF_MODE?.startsWith('C')) {
+    const { runConcurrentAcceptance } = await import('./app-perf-concurrent.mjs')
+    await runConcurrentAcceptance({ app, win, js, waitFor, settle, clickSelector, typeText, measure, seed, report, writeReport, screenshot, directory, artifacts, composer, sendButton, stopButton, retainedHeapMB })
+    clearTimeout(deadline)
+    writeReport()
+    app.exit(report.status === 'passed' ? 0 : 1)
+    return
+  }
+
   const idle = await measure('idle', 'Fresh profile, no interaction for 3 s', async () => { await sleep(3_000) })
   frameBaseline = idle.renderer.frames.p50 ?? 16.7