fix(rebase): migrate the replayed stack onto current master APIs

The linear replay carried each commit's own lineage, so this checkpoint
restores the master-owned surfaces the conflicted regions clobbered and
migrates branch-owned code to master's post-rebase APIs:

- rebuild subprocess-local spawn.ts on master's tree-exit-observer
  machinery, keeping the branch's win32 childEnv key semantics and the
  Linux zombie-quiescence probe; the zombie test reaps its survivor
  directly since a confirmed-absent verdict is a permanent
  no-more-signals boundary
- migrate pty-local test stubs to the Inbox-model Agent interface,
  Session.create, runnerFailureRules, and the new turn/start payload
- implement the seam's resolveExecutable/spawnTerminal abstracts in the
  new pwsh-local and tool-fs-search test fakes
- restore code-runtime, atomic-write, pwsh-local, and app-boot to
  master's exact content (the net-zero code-runtime churn is pruned
  from this history) and drop rename-detection graft debris
- re-apply the PR's architecture rows and execution-world paragraph,
  re-record bilingual pairings, regenerate catalogs, and reconcile the
  lockfile

packages/lsp/lsp-local/README.md

@@ -24,7 +24,7 @@ The `servers` record key is the stable provider id reserved on `ctx.lsp`; each v
 |---|---|---|
 | `command` | (required) | Executable to spawn — absolute, or resolved on the child PATH at load. Launch uses no shell. |
 | `args` | `[]` | Arguments passed to the executable. |
-| `env` | `{}` | Extra env merged on top of the credential-scrubbed ambient env (vars matching `KEY`/`SECRET`/`TOKEN` are not forwarded); an explicit `DSH_*` entry merges after the seam's scrub of ambient ones. |
+| `env` | `{}` | Extra env merged on top of the credential-scrubbed ambient env (vars matching `KEY`/`PASSWORD`/`SECRET`/`TOKEN` are not forwarded); an explicit `DSH_*` entry merges after the seam's scrub of ambient ones. |
 | `extensionToLanguage` | (required) | Lowercase leading-dot extension → LSP language id (e.g. `{ '.ts': 'typescript' }`). |
 | `initializationOptions` | `null` | Static `initialize` options forwarded to the server. |
 | `configuration` | `null` | Static answer to every `workspace/configuration` item. |