feat(semble): upgrade to v0.4.1, flatten result parsing, localize status messages (#734)

* feat(semble): upgrade to v0.4.1, flatten result parsing, localize status messages

- Bump SEMBLE_VERSION v0.3.1 -> v0.4.1 and refresh SEMBLE_SHA256 checksums
- Adapt to semble v0.4.0+ flat JSON output (no chunk wrapper); remove
  SembleChunk and flatten SembleSearchResult (file_path, start_line,
  end_line, score, content)
- Update provider.ts and semble-cli.ts parsing accordingly
- Version-prefix the local archive cache path so a stale archive from a
  previous semble version is never reused or verified against the new
  checksum; remove partial archive before re-downloading
- Add cleanupStaleArchives to best-effort sweep orphaned archives after
  a version upgrade
- Localize SembleProvider status strings via i18n embeddings:semble.*
  keys across all 18 locales
- Update provider/cli/downloader unit tests for the new shape and
  version-prefixed cache path

Closes #733

* fix(semble): clean legacy unversioned archives and cover stale-archive sweep

CodeRabbit PR #734 follow-ups:

- cleanupStaleArchives now also matches the exact unversioned archive name
  (pre-v0.4.0 cache layout) in addition to the version-prefixed suffix, so a
  v0.3.1 -> v0.4.1 upgrade also clears the legacy file. The current archive
  path is still preserved.
- semble-downloader.spec: the version-upgrade test now simulates a prior-version
  archive (v0.4.0-*) and a legacy unversioned archive in the cache, and asserts
  both are swept during the upgrade flow.
- Add coverage for the cleanupStaleArchives catch block (readdir rejects) and
  for the current-archive/unrelated-file preservation behavior.
- provider.spec: add a test that rejects search with a non-Error value to cover
  the 'error instanceof Error' false branch of the telemetry payload (stack:
  undefined), raising provider.ts patch coverage.

* feat(semble): surface active version in the CodeIndexPopover status message

Export SEMBLE_VERSION from semble-downloader and re-export from the semble
barrel. SembleProvider now interpolates the active version into the
'embeddings:semble.ready' system-state message (set in both _doInitialize and
startIndexing), so the CodeIndexPopover status line shows e.g.
'Indexed - Semble v0.4.1 is ready. Searches index on-the-fly.'

- semble-downloader.ts: export SEMBLE_VERSION.
- index.ts: re-export SEMBLE_VERSION.
- provider.ts: pass { version: SEMBLE_VERSION } to t('embeddings:semble.ready').
- i18n: update semble.ready across all 18 locales to include {{version}}.
- provider.spec.ts: mock SEMBLE_VERSION, update the ready-message mock to
  interpolate version, and add a test asserting the version appears in the
  ready status message.

* fix review comments

Author: navedmerchant

src/i18n/locales/ca/embeddings.json

@@ -72,5 +72,13 @@
 		"indexingRequiresWorkspace": "Indexing requires an open workspace folder",
 		"indexingStopped": "Indexing stopped by user.",
 		"indexingStoppedPartial": "Indexing stopped. Partial index data preserved."
+	},
+	"semble": {
+		"downloadingBinary": "Downloading semble binary...",
+		"ready": "Semble {{version}} is ready. Searches index on-the-fly.",
+		"unsupportedPlatform": "Semble is not supported on this platform ({{platform}}-{{arch}}).",
+		"downloadFailed": "Failed to download semble: {{errorMessage}}",
+		"checkFailed": "Semble check failed: {{errorMessage}}",
+		"providerReset": "Semble provider reset. On-disk cache remains until next rebuild."
 	}
 }