feat(fase-14): version chip in /settings + GIT_SHA bake-through (14.3)

`apps/web/vite.config.ts` now injects three build-time constants via
`define`: `__APP_VERSION__` (root package.json), `__APP_COMMIT__`
(GIT_SHA env > local `git rev-parse` > 'dev'), `__BUILD_TIME__` (ISO
timestamp at build). They're declared in `apps/web/src/global.d.ts`
and re-exported through `$lib/version` — components consume the named
exports rather than the magic globals so an accidental tree-shake
would break the test, not the page silently.

`/settings` gains an "About" section at the bottom: a small chip
`v{version} · {commit} · {date}` in muted text. Not interactive,
purely diagnostic — useful when a user reports a bug from a stale
PWA install.

Deploy pipeline:
  - `apps/web/Dockerfile` accepts a `GIT_SHA` build arg and exports
    it as an env var for the SvelteKit build step.
  - `infra/docker-compose.erosi.yml` forwards `${GIT_SHA:-dev}` into
    the build args.
  - `infra/scripts/deploy-erosi.sh` captures `git rev-parse --short
    HEAD` locally (the deploy host has .git; the remote doesn't —
    rsync excludes it) and forwards it via `ssh ... env GIT_SHA=…`
    so the remote `docker compose build` sees it.

V-01/V-02 vitest: stub the three globals via `vi.stubGlobal` (vitest
doesn't run through the main vite.config so `define` isn't applied),
assert the named exports thread through and never collapse to
undefined or the 'dev' sentinel under a real build.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

infra/docker-compose.erosi.yml

@@ -178,6 +178,10 @@ services:
         PUBLIC_KEYCLOAK_REALM: ${PUBLIC_KEYCLOAK_REALM}
         PUBLIC_KEYCLOAK_CLIENT_ID: ${PUBLIC_KEYCLOAK_CLIENT_ID}
         PUBLIC_APP_URL: ${PUBLIC_APP_URL}
+        # Fase 14.3.5 — short git sha of the host's checkout, exported
+        # by infra/scripts/deploy-erosi.sh before invoking the build.
+        # Defaults to literal 'dev' if the deployer didn't set GIT_SHA.
+        GIT_SHA: ${GIT_SHA:-dev}
     restart: always
     environment:
       PUBLIC_SUPABASE_URL: ${PUBLIC_SUPABASE_URL}