fix(mcp,extraction): exit a daemon whose install changed; never store a grammar-load failure (#2335, #2336) (#2346)

* fix(mcp,extraction): a daemon whose install changed exits; grammar-load failures are never stored (#2335, #2336)

A daemon that outlived an upgrade loaded grammars lazily from an install
that no longer existed, and stored every file its watcher re-indexed as a
zero-node row under the file's new content hash: no hash-based sync ever
revisited those rows, and `codegraph status` called the index up to date.

- The daemon checks its own package.json every 30 s
  (CODEGRAPH_DAEMON_INSTALL_CHECK_MS, 0 turns it off) and exits once the
  file is gone or carries another version, so the next session starts a
  daemon from the current install.
- A result whose grammar failed to load (`parser_error`) is never stored:
  the file keeps its previous data and the next sync or index retries it,
  and a row an older engine stored that way is re-indexed even though its
  hash matches. The tag-based CFML path reports a missing grammar with the
  same code.
- A launcher whose own install was deleted no longer crashes on the spawn
  error of the daemon it tried to start.
- `codegraph status` and `status --json` (filesNeedingReindex,
  filesWithParseErrors) report indexed files whose symbols are missing
  although their content is current (#2336), and `files --json` carries
  each file's recorded errors.

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

* fix(mcp): a session whose own install changed never claims the writer lock (#2335)

A daemon now exits once its install is upgraded or removed, and nobody
holds the writer slot for a successor at that point. Its sessions run the
same replaced code and serve themselves in-process the moment it goes; one
that found the slot free claimed it as its writer even though its engine
could not load (a real npm upgrade: "Cannot find module
'./sqlite-adapter'"), and so kept a daemon from the current install from
starting. Such a session now falls back read-only and says to restart it.

Also adds the CHANGELOG entries for the install check and grammar-load
failures (#2335) and for the status report (#2336).

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

---------

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

src/types.ts

@@ -265,6 +265,24 @@ export interface FileRecord {
   generated?: boolean;
 }
 
+/**
+ * Indexed files whose symbols are missing even though their content hash is
+ * current — what a hash comparison alone calls "up to date" (#2336). Paths are
+ * project-relative and sorted.
+ */
+export interface IndexHealth {
+  /**
+   * Files `sync` re-indexes: stored while their grammar could not load (#2335)
+   * or stored with no nodes and no recorded reason (#1541).
+   */
+  needsReindex: string[];
+  /**
+   * Files with a recorded parse error and no symbols from it. Deterministic:
+   * they stay this way until the file (or the parser) changes.
+   */
+  parseErrors: string[];
+}
+
 // =============================================================================
 // Extraction Types
 // =============================================================================