enhance(#4570): allow disabling planner stall detection (#4585)

* enhance(#4570): allow disabling planner stall detection

* docs(#4570): add changelog fragment

Emitted-Drift-Ack-Growth: plan-phase.md — the explicit opt-out gate covers all five planner and checker spawn classes
Emitted-Drift-Ack-Growth: settings-advanced.md — the toggle prompt and bounded-recovery warning expose the new setting

* chore(#4570): refresh compact-content baseline

* fix(#4570): preserve default-on watchdog fallback

* docs(#4570): qualify the chunked-mode orchestrator rules with the toggle

The two chunked-planning-mode stall-watch imperatives read as
unconditional, with the opt-out stated only in a following bullet. State
the PLANNER_STALL_DETECTION_ENABLED condition inline, matching the three
sites already qualified in plan-phase.md.

* chore(#4570): refresh compact-content baselines against rebased next

* fix(#4570): sync planner stall launcher

Keep the stall-detection helper aligned with the canonical runtime launcher.

* chore(#4570): refresh compact baseline after rebase

---------

Co-authored-by: Tom Boucher <trekkie@nomorestars.com>

CONTEXT.md

@@ -280,6 +280,8 @@ Module owning agent-presence resolution and verification, extracted from the Cor
 ### Config Loader Module
 Module owning project configuration loading: reads `.planning/config.json`, merges built-in defaults (`CONFIG_DEFAULTS`/`CANONICAL_CONFIG_DEFAULTS`), normalizes legacy keys, applies the active-workstream overlay, validates against the config schema, and warns on unknown keys/profile overrides. Primary interface: `loadConfigResolved(cwd, options) → ConfigResolution { config, source, degraded }` (provenance-aware, ADR-1411 P2 / #1415) — `source` ∈ `'workstream' | 'root' | 'builtin-defaults' | 'global-defaults'`; `degraded:true` when a workstream was requested but its config.json was absent (fell back to root config). `loadConfig(cwd, options) → Record<string,unknown>` is the back-compat thin wrapper over `loadConfigResolved` (byte-identical result). Loading is **not side-effect-free by default**: normalizing a legacy key marks the config dirty and writes the migrated shape back to disk, which is how a legacy project is migrated by ordinary use. `options.persist: false` (#3648) suppresses exactly that write while leaving resolution identical — the option a caller passes when it is only ASKING the config something (the Git Query Module's protected-branch predicate runs on every `execute-phase` and `ship`, and a question must not rewrite the file it asks about). It is opt-OUT, so every pre-existing caller keeps the historical write-back. Resolution is **caller-anchored, not loader-anchored**: `loadConfigResolved` resolves `cwd` as-is (no walk-up), so `loadConfig` stays byte-identical for its callers; callers that need cwd-drift tolerance (e.g. `cmdAgentSkills`) anchor to the project root via `findProjectRoot` (Project-Root Resolution Module) *before* calling `loadConfigResolved`. Helper exports: `_deepMergeConfig`, `isGitIgnored`, `_warnUnknownProfileOverrides`. Depends only on leaf modules (`configuration`, `config-schema`, `planning-workspace`, `shell-command-projection`, `core-utils`, `model-catalog`) — no other core dependency. Extracted from the Core module per ADR-857 rollout phase 2e (#885) as the prerequisite for the model-resolver extraction (the resolvers call `loadConfig`); the `core.cjs` re-export spine was retired in epic #1267, so callers import this leaf directly. Source of truth: `gsd-core/bin/lib/config-loader.cjs` (generated from `src/config-loader.cts`).
 
+`planner.stall_detection_enabled` (#4570) is a central, default-on boolean projected as `planner_stall_detection_enabled` by this module. Root/workstream overlay happens before its type resolution; only a real boolean is honored, while an absent or hand-edited non-boolean value fails safe to the manifest default `true`. The plan-phase workflow reads it through `query config-get`, never by parsing config JSON locally, so root/project/workstream routing remains owned by the canonical configuration seams.
+
 ### Planning Publication Gate (`planning.pr_strict`)
 The seam deciding whether `.planning/` artifacts reach the REMOTE — distinct from the Planning Commit Gate below, which decides whether they reach git at all. `planning.pr_strict` (boolean, manifest default `false`) resolves through the same `loadConfigResolved` chain as its `planning.*` siblings (explicit top-level `pr_strict`, then the `planning.pr_strict` alias, then the manifest default), and is additionally registered in `SCHEMA_DEFAULTS` (`src/config.cts`) so `query config-get planning.pr_strict` answers `false` for an absent key rather than `Key not found` — `gsd-core/workflows/pr-branch.md` reads it with a plain `config-get` and must not special-case a missing key. It selects between two filter modes in that workflow: default preserves the five structural planning files plus `milestones/**` and drops nine transient subdirectories; strict drops every `.planning/` path and includes a commit only when it touches at least one file outside `.planning/`. The two path lists are declared ONCE in the workflow (`TRANSIENT_DIRS`, `STRUCTURAL_RE`) and both the un-stage step and the verification assertion are derived from them, because the prior shape declared them twice and the two steps disagreed by construction — `verify` asserted zero `.planning/` paths while `create_pr_branch` was specified to preserve five, so a correct run reported itself as failed on every phase (#2971). A third gate is deliberately NOT derived from those declarations: `PLANNING_DELETIONS` (#3679) counts DELETED `.planning/` paths via `git diff --name-status --no-renames` and must be `0` in every mode — a deleted planning path is data loss, not filtering, and name-only counting cannot see status. The two gates are independent but not orthogonal in effect: `pr_strict` is inert when `commit_docs` is `false`, since nothing is committed for the PR-branch filter to remove. Source of truth: `gsd-core/workflows/pr-branch.md`; key registered in `gsd-core/bin/shared/config-{defaults,schema}.manifest.json`.