fix(lsp): address codex review round 1

Lifecycle and safety fixes from the external review:
- Observe abort while awaiting the initialize handshake, so a server that never
  replies can't defeat the tool-timeout signal.
- On an aborted request the server won't cancel, tear the instance down after a
  bounded grace instead of releasing the serialized queue with work still live
  (prevents overlapping document lifecycles).
- Re-check provider disposal after the canonicalize/read awaits so a query can't
  spawn an unowned server after disposeAll().
- Read the source through one open handle (stat + read on the same fd) to close
  the realpath-vs-read TOCTOU; decode with a fatal UTF-8 decoder so a legitimate
  U+FFFD is not misclassified as invalid.
- Validate and read the source BEFORE spawning a server (pre-start rejection).
- Require an explicit openClose for option-form textDocumentSync.
- Reject nonpositive teardown budgets and non-executable absolute commands at
  load; surface unsupported operations as structured LSP_UNSUPPORTED_OPERATION.
- Retain the stderr tail (fatal diagnostics land at exit), not the prefix.
- Catalog the seam vocabulary in docs/core-data-structures/lsp.md.

docs/core-data-structures/core.md

@@ -28,6 +28,7 @@ Everything else is documented on a **sub-page**, not here. The rule that draws t
 | [sandbox.md](sandbox.md) | the process-confinement seam: file-effect modes, `SandboxPolicy`, `ConfinedArgv`, enforcement and fail-closed errors |
 | [code-runtime.md](code-runtime.md) | the code-execution seam: `CodeRunRequest`/`Result`, binding namespaces, captured logs, the `CodeRunFailure` taxonomy |
 | [filesystem.md](filesystem.md) | the filesystem seam: `FsTarget`, read/write/edit outcomes, observed-file state, `FsErrorCode` |
+| [lsp.md](lsp.md) | the LSP navigation seam: `LspQueryRequest`/`Result`, `LspProvider`/`Service`, four operations, `LspError` |
 | [skills.md](skills.md) | the skill service: discovery priority, `SkillSummary`/`SkillDefinition`, session-prefix catalog, model-facing `skill` loading |
 | [compaction.md](compaction.md) | the compaction seam: the `compact/*` session events, `CompactionResult`, the `CompactService` interface |
 | [subagent.md](subagent.md) | the subagent seam: the named-provider registry, `SubagentStartRequest`/`Result`/`Run`, the start-time-vs-runtime capability split |