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>

tests/fixtures/compact-content-benchmark-baseline.json

@@ -28,9 +28,9 @@
       "reductionPct": 13.53
     },
     "plan-phase": {
-      "offTokens": 28000,
-      "onTokens": 24649,
-      "reductionPct": 11.97
+      "offTokens": 28406,
+      "onTokens": 25055,
+      "reductionPct": 11.8
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     "verify-work": {
       "offTokens": 13445,
@@ -39,8 +39,8 @@
     }
   },
   "aggregate": {
-    "offTokens": 108858,
-    "onTokens": 91988,
-    "reductionPct": 15.5
+    "offTokens": 109264,
+    "onTokens": 92394,
+    "reductionPct": 15.44
   }
 }

tests/fixtures/compact-content-variant-benchmark-baseline.json

@@ -23,9 +23,9 @@
       "reductionPct": 20.79
     },
     "agents/gsd-code-fixer.md": {
-      "offTokens": 10740,
-      "onTokens": 6690,
-      "reductionPct": 37.71
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+      "onTokens": 6781,
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     "agents/gsd-code-reviewer.md": {
       "offTokens": 4408,
@@ -38,9 +38,9 @@
       "reductionPct": 9.76
     },
     "agents/gsd-debug-session-manager.md": {
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-      "onTokens": 4738,
-      "reductionPct": 5.75
+      "offTokens": 5088,
+      "onTokens": 4799,
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     },
     "agents/gsd-doc-classifier.md": {
       "offTokens": 2901,
@@ -73,9 +73,9 @@
       "reductionPct": 17.83
     },
     "agents/gsd-eval-auditor.md": {
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-      "onTokens": 2808,
-      "reductionPct": 4.52
+      "offTokens": 3002,
+      "onTokens": 2869,
+      "reductionPct": 4.43
     },
     "agents/gsd-eval-planner.md": {
       "offTokens": 1674,
@@ -93,9 +93,9 @@
       "reductionPct": 42.1
     },
     "agents/gsd-intel-updater.md": {
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-      "onTokens": 4115,
-      "reductionPct": 5.47
+      "offTokens": 4414,
+      "onTokens": 4176,
+      "reductionPct": 5.39
     },
     "agents/gsd-mempalace-curator.md": {
       "offTokens": 1160,
@@ -113,14 +113,14 @@
       "reductionPct": 15.37
     },
     "agents/gsd-project-researcher.md": {
-      "offTokens": 5464,
-      "onTokens": 5135,
-      "reductionPct": 6.02
+      "offTokens": 5525,
+      "onTokens": 5196,
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     },
     "agents/gsd-research-synthesizer.md": {
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-      "onTokens": 2917,
-      "reductionPct": 6.57
+      "offTokens": 3183,
+      "onTokens": 2978,
+      "reductionPct": 6.44
     },
     "agents/gsd-roadmapper.md": {
       "offTokens": 6008,
@@ -133,9 +133,9 @@
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     "agents/gsd-ui-auditor.md": {
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       "onTokens": 3926,
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+      "reductionPct": 41.66
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     "agents/gsd-ui-checker.md": {
       "offTokens": 4499,
@@ -143,9 +143,9 @@
       "reductionPct": 32.25
     },
     "agents/gsd-ui-researcher.md": {
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-      "reductionPct": 11.36
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     },
     "agents/gsd-user-profiler.md": {
       "offTokens": 1859,
@@ -163,14 +163,14 @@
       "reductionPct": 33.87
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     "gsd-core/workflows/help/modes/full.md": {
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   "aggregate": {
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-    "onTokens": 94602,
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+    "offTokens": 121986,
+    "onTokens": 95053,
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 }