test(performance): count startup phases and SQL statements for the J1 launch journey

Implements plan item A2. With IPTVNATOR_PERF_CAPTURE=1 the main process
keeps named counters and registers a main-only performance:read-counters
IPC handler; without the flag nothing is counted and the handler does not
exist.

- debug-trace.ts owns the registry; traceStartupPhase replaces the
  trace('startup', ...) sites and counts main.startupPhases.
- The database worker counts executed statements through better-sqlite3's
  Statement prototype (the verbose callback expands every statement and
  made bulk inserts 2-4x slower) and posts the count over its message
  port, flushed before every other worker message. The main-thread shared
  connection is counted through a new connection observer in the shared
  database library.
- The first main window freezes main.modulesRegisteredBeforeWindow at
  creation and main.sqlStatementsBeforeReadyToShow at ready-to-show.
- The journey gate drops the ready-to-show that Electron emits for the
  about:blank detour, so the app sees the real document's first paint,
  and taps the counters handler; the J1 record reads both counters after
  the renderer probe completes.

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

docs/development/electron-debugging.md

@@ -30,7 +30,7 @@ IPTVNATOR_TRACE_STARTUP=1 pnpm nx serve electron-backend
     - `IPTVNATOR_TRACE_WINDOW=1` traces BrowserWindow lifecycle and unresponsive events
     - `IPTVNATOR_TRACE_PLAYER=1` traces external-player activity and bounded Embedded MPV runtime-probe stderr
     - `IPTVNATOR_TRACE_RENDERER_CONSOLE=1` mirrors renderer console output into the Electron terminal
-    - `IPTVNATOR_PERF_CAPTURE=1` enables development/test-only, redacted M3U and Xtream preload IPC request/completion markers plus count-only M3U acquire/parse/normalize, Xtream main network/JSON-transform/success-response-ready/cancel-dispatch, and renderer store phase capture; renderer wrappers emit only while the benchmark installs its Symbol hook, benchmark tooling sets the flag explicitly, and production launches must leave it unset
+    - `IPTVNATOR_PERF_CAPTURE=1` enables development/test-only, redacted M3U and Xtream preload IPC request/completion markers plus count-only M3U acquire/parse/normalize, Xtream main network/JSON-transform/success-response-ready/cancel-dispatch, and renderer store phase capture; renderer wrappers emit only while the benchmark installs its Symbol hook, benchmark tooling sets the flag explicitly, and production launches must leave it unset. It also keeps count-only main-process counters (startup phases, database worker SQL statements, and their values at main-window creation and `ready-to-show`) and registers the main-only `performance:read-counters` IPC handler, which the preload does not expose; see [performance journeys](../architecture/performance-journeys.md)
     - `IPTVNATOR_PERF_WORKER_PROFILING=1` enables development/test-only, request-scoped worker receive/work/response-post timestamps, thread CPU, event-loop utilization/delay, count-only playlist serialization/SQLite write/read/deserialization plus Xtream category/content/cache-clear/delete/in-source-search phase events, profiling-only worker cancel-receipt acknowledgements, valid-sample-counted isolate peak memory, and the database worker's idle-only one-shot post-GC heap probe; overlapping database requests are explicitly invalidated instead of misattributed, the performance benchmark sets the flag automatically, and production launches must leave it unset
     - `IPTVNATOR_DISABLE_COMPILE_CACHE=1` disables the main-process V8 compile cache; `IPTVNATOR_COMPILE_CACHE_DIR=<dir>` relocates it. The startup trace reports the outcome as `compile-cache`