tool-switch: create the missing counterpart file instead of silently no-opping

Tools → "Switch to PCB Editor" in a project with no .kicad_pcb (e.g. created
from a lone schematic) did nothing: the nav hook found no file for the target
tool and returned false. Now a session that can persist (ToolPage passes the
new createFile prop) writes the templated counterpart via
createProjectFileIfMissing — no download fallback, and it re-checks existence
so a collaborator's file is never clobbered — then navigates to it, matching
native KiCad (pcbnew opens a new board at the derived path). Sessions that
can't persist (read-only viewers, scratch/local-folder) keep the logged no-op.

Also latch the quit dispatcher off before every deliberate tool-switch
navigation (markDeliberateNavigation): the wx port's UnloadCallback runs on
BEFOREUNLOAD and closes the top frame the moment the navigation starts, so
the quit hook history.back()'d over the in-flight navigation — the pagehide
latch is too late (it only fires at commit time).

e2e: new tests/web/tool-switch-missing-file.spec.ts reproduces the flow via a
browser-local (IDB) project created from the home page; playwright-web config
gains VITE_LOCAL_PROJECTS=idb and derives STANDALONE_PORT/CORS_ORIGIN from
WEB_APP_URL (runs the suite past a squatted :3048); both vars declared in
web/turbo.json globalEnv (turbo strict-env strips undeclared vars). Includes
the previously-uncommitted tool-switch spec repairs (URL grammar + z-30
boot-overlay wait).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

web/turbo.json

@@ -2,10 +2,12 @@
   "$schema": "https://turbo.build/schema.json",
   "globalEnv": [
     "PORT",
+    "STANDALONE_PORT",
     "PROJECT_DIR",
     "CORS_ORIGIN",
     "WASM_SRC_DIR",
     "VITE_API_BASE_URL",
+    "VITE_LOCAL_PROJECTS",
     "VITE_WASM_ASSET_BASE_URL"
   ],
   "tasks": {