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

docs/cordis-catalog/services.md

@@ -594,6 +594,34 @@ Abstract filesystem provider. Targets must preserve identity across aliases; rea
  */
 abstract resolve(path: string, opts?: { cwd?: string; signal?: AbortSignal }): Promise<FsTarget>
 
+/**
+ * Return the canonical absolute path a subprocess in this filesystem's
+ * execution world can open. The path is deliberately separate from
+ * {@link FsTarget.targetKey}: consumers may pass this value to another OS
+ * capability, but must continue treating the target key as opaque.
+ * @param target - the resolved target whose process path is required.
+ * @returns an absolute path in the backend's execution world.
+ */
+abstract processPath(target: FsTarget): string
+
+/**
+ * Return the canonical `file:` URI for a target in this filesystem's
+ * execution world. Backends own URI encoding because the host platform may
+ * differ from the execution platform.
+ * @param target - the resolved target to encode.
+ * @returns the target's canonical file URI.
+ */
+abstract fileUrl(target: FsTarget): string
+
+/**
+ * Test canonical containment without exposing or parsing backend target
+ * keys. Both targets must come from this provider.
+ * @param parent - canonical directory target.
+ * @param child - canonical candidate target.
+ * @returns true when `child` is `parent` or a descendant of it.
+ */
+abstract contains(parent: FsTarget, child: FsTarget): boolean
+
 /**
  * Return target metadata, or `undefined` when the target does not exist.
  * @param target - the resolved target to stat.
@@ -678,7 +706,7 @@ abstract editText( target: FsTarget, edit: FsEditRequest, expected?: { version:
 
 Types: [FsDirEntry](../core-data-structures/filesystem.md) · [FsEditOutcome](../core-data-structures/filesystem.md) · [FsEditRequest](../core-data-structures/filesystem.md) · [FsInfo](../core-data-structures/filesystem.md) · [FsPathInfo](../core-data-structures/filesystem.md) · [FsTarget](../core-data-structures/filesystem.md) · [FsVersion](../core-data-structures/filesystem.md) · [FsWriteIntent](../core-data-structures/filesystem.md) · [FsWriteOutcome](../core-data-structures/filesystem.md) · [SandboxExecutionPolicy](../core-data-structures/sandbox.md)
 
-Source: [`packages/fs/fs/src/index.ts:81`](../../packages/fs/fs/src/index.ts)
+Source: [`packages/fs/fs/src/index.ts:83`](../../packages/fs/fs/src/index.ts)
 
 ## `ctx.goals` — `GoalService`
 
@@ -2215,12 +2243,27 @@ Abstract subprocess service. Subclass, implement spawn, and load the subclass as
 
 Implementations must honor these semantics:
 
+- Executable paths belong to one execution world shared with the mounted filesystem provider.
 - spawn returns immediately with a live handle; `done` resolves at process close with exit facts and rejects only for spawn-level failures.
 - Collect-mode readers are offset-based and non-consuming, so independent readers never consume one another's output; lossy reads report truncation and the spill file holding the complete stream when one exists. Piped streams are handed to the caller raw and never buffered here.
 - SubprocessHandle.terminate (and the spec's abort signal) escalates SIGTERM→grace→SIGKILL — the only termination verb — tree-scoped on every platform. SubprocessHandle.waitForExit observes whole-tree liveness, so a consumer-owned teardown ladder can hold each tier on real quiescence.
 - Disposal of the service terminates all still-running managed processes and awaits their exit.
+- spawnTerminal owns terminal allocation, text transport, foreground groups, signalling, and whole-session quiescence behind one awaited termination method; readiness and persistent-shell policy stay in the PTY consumer. Its output stream ends after queued terminal output when the top-level process exits.
 
 ```ts cordis-catalog
+/**
+ * Resolve one configured executable in this provider's execution world.
+ * Absolute paths are verified; bare names use the provider's scrubbed PATH
+ * plus explicit environment overrides. Relative paths containing separators
+ * are rejected: no current consumer defines which directory they would
+ * resolve against, so providers fail loud instead of guessing.
+ * @param command - absolute executable path or bare PATH name.
+ * @param env - explicit environment entries used for lookup.
+ * @param signal - aborts remote or local lookup.
+ * @returns a canonical executable path.
+ */
+abstract resolveExecutable( command: string, env?: Readonly<Record<string, string>>, signal?: AbortSignal, ): Promise<string>
+
 /**
  * Start one managed child process from a fully-specified spec; this seam
  * applies no defaults.
@@ -2228,11 +2271,20 @@ Implementations must honor these semantics:
  * @returns the live process handle (streams/readers, signalling, outcome promise).
  */
 abstract spawn(spec: SubprocessSpawnSpec): SubprocessHandle
+
+/**
+ * Allocate a real terminal and start one owned process session. This is the
+ * only non-pipe process primitive: implementations own terminal byte I/O,
+ * foreground groups, signals, and complete session-tree cleanup.
+ * @param spec - fully specified argv, cwd, environment, dimensions, grace, and allocation cancellation.
+ * @returns the live terminal handle after allocation succeeds.
+ */
+abstract spawnTerminal(spec: SubprocessTerminalSpawnSpec): Promise<SubprocessTerminalHandle>
 ```
 
-Types: [SubprocessHandle](../core-data-structures/subprocess.md) · [SubprocessSpawnSpec](../core-data-structures/subprocess.md)
+Types: [SubprocessHandle](../core-data-structures/subprocess.md) · [SubprocessSpawnSpec](../core-data-structures/subprocess.md) · [SubprocessTerminalHandle](../core-data-structures/subprocess.md) · [SubprocessTerminalSpawnSpec](../core-data-structures/subprocess.md)
 
-Source: [`packages/subprocess/subprocess/src/index.ts:91`](../../packages/subprocess/subprocess/src/index.ts)
+Source: [`packages/subprocess/subprocess/src/index.ts:102`](../../packages/subprocess/subprocess/src/index.ts)
 
 ## `ctx.systemPrompt` — `SystemPrompt`