Svelte + TypeScript: fail loudly on companion TS timeouts; deterministic test fixture

Make the Svelte companion TypeScript server raise on readiness and
indexing timeouts instead of silently proceeding with a partial index,
turning flaky/wrong cross-file results into clear failures:

- TypeScriptLanguageServer: timeout handling factored into overridable
  hooks (_handle_server_ready_timeout, _handle_project_indexing_timeout);
  the base server keeps its historical permissive behavior, so plain
  TypeScript setups are unchanged.
- SvelteTypeScriptServer: both overrides raise TimeoutError; only the
  indexing-timeout error includes describe_indexing_state(), instead of
  serving requests from a cold or partially indexed program.
- Configurable server_ready_timeout / indexing_timeout via
  ls_specific_settings.
- SvelteLanguageServer: file-open failures during companion preparation
  raise SvelteCompanionPreparationError with a count-first file listing
  (capped at 10), chained to the first underlying error so the cause is
  visible without DEBUG logging.

Apply the same fail-loudly principle to the test fixture bootstrap:

- Svelte test repo: npm ci with a committed package-lock.json, removing
  dependency-resolution non-determinism from CI runs.
- Run svelte-kit sync explicitly during fixture setup and fail loudly if
  .svelte-kit/tsconfig.json cannot be generated. The fixture's "prepare"
  script masks sync failures ("svelte-kit sync || echo ''"), and a known
  npm bug (npm/cli#4828) can silently skip platform-specific optional
  dependencies; the result is unresolvable $lib path aliases and
  cross-file tests failing with partial results instead of a clear,
  actionable error.
- codespell: skip third-party fixture repositories, using the anchored
  pattern ./test/resources/repos (codespell matches skip globs against
  the ./-prefixed paths it walks, so an anchor-less pattern never
  matches).

Also add direct regression tests for the timeout-policy split
(test/solidlsp/test_typescript_timeout_policy.py: base stays
permissive, companion raises, settings plumbing and precedence, and
start-or-completion indexing-wait semantics). The tests use no mocking or
patching of any kind; a hand-written call-recording fake drives the companion
guard against real file discovery under a pytest tmp_path. They spawn no LS
process and avoid external readiness races; one wait test uses a real Timer
with a 30s ceiling.

The configuration docs state that the TypeScript table lists both knobs; the
Svelte table lists indexing_timeout, with readiness inheritance documented in
prose.

docs/02-usage/050_configuration.md

@@ -1031,6 +1031,7 @@ Supported settings:
 | `typescript_language_server_version` | `5.1.3` | Override the bundled `typescript-language-server` npm package version Serena installs when `ls_path` is not set. |
 | `npm_registry` | `null` | Override the npm registry Serena uses for the managed install. |
 | `indexing_timeout` | `30.0` | Timeout in seconds for waiting on tsserver's `$/progress` project-indexing signal (both at startup and before the first cross-file reference query). If indexing does not complete within this window, Serena logs a warning and proceeds anyway. Increase it for very large projects. |
+| `server_ready_timeout` | `10.0` | Timeout in seconds for waiting on the server-ready signal after initialization. If the signal does not arrive within this window, Serena logs a message and proceeds anyway. |
 
 #### Svelte
 
@@ -1048,8 +1049,15 @@ Supported settings:
 | `typescript_language_server_version` | `5.1.3` (falls back to `ls_specific_settings.typescript.typescript_language_server_version`) | Override the `typescript-language-server` npm package version for the companion server. |
 | `typescript_svelte_plugin_version` | `0.3.52` | Override the `typescript-svelte-plugin` npm package version used for `.svelte`-aware TS resolution. |
 | `npm_registry` | `null` | Override the npm registry Serena uses for all managed installs. |
+| `indexing_timeout` | `120.0` (falls back to `ls_specific_settings.typescript.indexing_timeout`) | Timeout in seconds for the companion TS server to finish indexing `.svelte` files. On timeout, startup fails with a diagnostic indexing-state summary instead of serving cross-file results from a partially indexed program. |
 | `initialization_options_configuration` | `{}` | Deep-merge overrides for any of the ten plugin configuration sections (`svelte`, `prettier`, `emmet`, `typescript`, `javascript`, `js/ts`, `css`, `less`, `scss`, `html`). |
 
+Unlike the plain TypeScript server, the companion is strict about readiness: it raises on server-ready and
+indexing timeouts instead of proceeding with a cold or partially indexed program (which would silently degrade
+cross-file renames and references). The companion reads `server_ready_timeout` and `indexing_timeout` from
+`ls_specific_settings.typescript` with raised defaults (30s and 120s respectively); `ls_specific_settings.svelte.indexing_timeout`
+takes precedence for the `.svelte`-file indexing wait.
+
 All four packages are tracked via a version file; changing any version setting triggers a clean reinstall.
 
 #### TypeScript via `vtsls`