docs: reserve seam for complete capabilities

packages/subprocess/subprocess/README.md

@@ -8,7 +8,7 @@ The subprocess seam (`ctx.subprocess`) is the process half of one execution worl
 
 - `spawn(spec)` returns immediately with a live handle; `done` resolves at process close with exit facts (`SubprocessOutcome` carries no output and no cause classification) and rejects only for spawn-level failures.
 - Spawn working directories and executable paths belong to the provider's execution world. `resolveExecutable(command, env?, signal?)` verifies absolute commands or resolves bare names against that world's scrubbed PATH plus explicit overrides.
-- The spec is fully explicit — argv, cwd, per-stream stdio dispositions, grace — because deployment-varying defaults belong to the calling seam's config, not to a hidden subprocess-service default (the `dsh-bash` request/spec split is the owning template). `argv` is never shell-interpreted; a consumer that wants a shell passes `['bash', '-c', command]` itself.
+- The spec is fully explicit — argv, cwd, per-stream stdio dispositions, grace — because deployment-varying defaults belong to the caller's config, not to a hidden subprocess-service default (the `dsh-bash` request/spec split is the owning template). `argv` is never shell-interpreted; a consumer that wants a shell passes `['bash', '-c', command]` itself.
 - Stdio is Node-shaped per stream: `'pipe'` hands the caller the raw stream for its own protocol framing (LSP JSON-RPC, ACP ndjson), `'inherit'` passes the parent descriptor through for diagnostics, and collect mode (`{ maxBytes, spill? }`) buffers a bounded tail with an optional full-stream spill file. Collect readers take whole-stream byte offsets and never consume, so independent readers cannot steal one another's deltas; a read whose offset slid out of the in-memory tail is `lossy` and points at the spill file when one exists. Collected output stays readable after settlement.
 - Termination is tree-scoped on every platform (POSIX detached groups with direct-child fallback; Windows `taskkill /T`): `terminate()` — the only termination verb — escalates SIGTERM→grace→SIGKILL (idempotent, driven by the spec's abort signal too, a no-op once the tree is gone), and `waitForExit(signal?)` observes whole-tree liveness so a consumer-owned teardown ladder holds each tier on real quiescence — the manager reacts but never classifies why (callers own deadlines, teardown ladders, and cause classification).
 - `spawnTerminal(spec)` is the only non-pipe primitive. Its handle owns a real PTY, UTF-8 text I/O, foreground-process-group inspection/signalling, and one awaited `terminate()` operation that reaches quiescence for every session member the provider can still observe and settles in-flight handle calls; providers document substrate-specific observability limits. The spec signal cancels allocation only; the published handle owns its lifetime. The output stream ends after queued output when the top-level process exits, and a live transport failure rejects `done`. These operations remain one substrate primitive because ordinary pipes cannot allocate a controlling terminal or clean terminal-session members; readiness, scrollback, and owner policy remain in the PTY consumer.
@@ -19,7 +19,7 @@ See the [subprocess subsystem page](../../../docs/subsystems/subprocess.md) and
 
 ## Model Experience
 
-Indirectly, through consumer seams (today the bash executor family behind `dsh-tool-bash`), which own all model-facing rendering of process output and lifecycle.
+Indirectly, through Consumers (today the bash executor family behind `dsh-tool-bash`), which own all model-facing rendering of process output and lifecycle.
 
 #### KV Cache effect