Improve in-flight cancel latency via run abort signal propagation

docs/api/PROTOCOL.md

@@ -700,6 +700,7 @@ Cancel the current agent operation.
 
 Used by the web dashboard/chat stop button and channel-level `/stop` / `/cancel` command fast-paths.
 Cancellation is best-effort and stops at the next agent/tool-loop safe point.
+Flynn now propagates a run-level abort signal into model/tool execution, so providers/tools that honor `AbortSignal` typically stop promptly instead of waiting for request/tool timeouts.
 
 ### Node Methods
 

docs/api/TOOLS.md

@@ -68,6 +68,8 @@ export interface ToolExecutionContext {
 }
 ```
 
+`signal` is wired to run-level cancellation (`agent.cancel`, `/stop`, `/cancel`) and tool timeout. Tools should honor it for fast cooperative aborts.
+
 ### ToolResult
 
 ```typescript

docs/plans/state.json

@@ -3,6 +3,27 @@
   "updated_at": "2026-02-19",
   "description": "Tracks the status of all Flynn plans and implementation phases",
   "plans": {
+    "faster-inflight-cancel-propagation": {
+      "status": "completed",
+      "date": "2026-02-19",
+      "updated": "2026-02-19",
+      "summary": "Reduced cancellation latency by wiring a run-level AbortSignal from NativeAgent into model and tool execution. `agent.cancel`/`/stop` now abort in-flight model/tool awaits immediately for signal-aware providers/tools instead of waiting for timeout/safe-point boundaries.",
+      "files_modified": [
+        "src/backends/native/agent.ts",
+        "src/tools/executor.ts",
+        "src/models/types.ts",
+        "src/models/openai.ts",
+        "src/models/github.ts",
+        "src/models/anthropic.ts",
+        "src/models/bedrock.ts",
+        "src/models/local/llamacpp.ts",
+        "src/backends/native/agent.test.ts",
+        "docs/api/PROTOCOL.md",
+        "docs/api/TOOLS.md",
+        "docs/plans/state.json"
+      ],
+      "test_status": "pnpm test:run src/backends/native/agent.test.ts src/tools/executor.test.ts src/models/router.test.ts src/gateway/handlers/agent.test.ts + pnpm typecheck passing"
+    },
     "makefile-skills-convenience-targets": {
       "status": "completed",
       "date": "2026-02-17",