fix(context,tools): context hygiene + tool ergonomics from freestyle QA

Found while live-QAing freestyle_planning on a 12B local model:

- list_dir tool: recursive, .gitignore-aware listing so weak models stop
  flooding context with `ls -R` over node_modules/build/dist. Wired into
  the fileRead toggle + advertised to the planner (architect_freestyle).
- ContextClassifier: assistantToolCall turns are STRUCTURED, so the token
  pruner never shreds the model's own tool-call history — that was causing
  amnesia loops (re-issuing calls it had already made).
- Retire instruction-doc LLMLingua pruning (DOC_SOURCE_TYPES emptied): it
  fused load-bearing procedural text into unparseable soup. The static
  block stays small by dropping CLAUDE.md at the loader instead.
- AgentInstructionsLoader: load only AGENTS.md, not CLAUDE.md — the latter
  targets the outer assistant and polluted the agent's stage context.
- DefaultSessionReducer: WorkflowFailed flips session status to FAILED (was
  stuck ACTIVE forever, so clients/approval loops never saw a terminal).
- ShellTool: run shell command lines (cd/&&/pipes) via `sh -c`; unrunnable
  program is recoverable instead of an uncaught IOException killing the
  stage; malformed argv (non-string/collapsed-array) rejected with guidance.
- llmlingua sidecar: cap force_tokens to max_force_token (big docs blew the
  assert and 500'd, so doc pruning silently failed open).

Tests added/updated across all of the above.

core/sessions/src/main/kotlin/com/correx/core/sessions/DefaultSessionReducer.kt

@@ -8,6 +8,7 @@ import com.correx.core.events.events.StageCompletedEvent
 import com.correx.core.events.events.StageFailedEvent
 import com.correx.core.events.events.StoredEvent
 import com.correx.core.events.events.TransitionExecutedEvent
+import com.correx.core.events.events.WorkflowFailedEvent
 
 class DefaultSessionReducer : SessionReducer {
 
@@ -22,6 +23,14 @@ class DefaultSessionReducer : SessionReducer {
             is StageFailedEvent ->
                 SessionStatus.FAILED
 
+            // A failed workflow is terminal for the session: no current workflow recovers after
+            // one fails (freestyle's planning→execution handoff only fires on WorkflowCompleted).
+            // Without this, an exhausted-retry WorkflowFailed left the session ACTIVE forever, so
+            // clients/approval loops never saw a terminal state. WorkflowCompleted is deliberately
+            // NOT mapped here — planning emits its own mid-session, so it isn't session-terminal.
+            is WorkflowFailedEvent ->
+                SessionStatus.FAILED
+
             is StageCompletedEvent,
             is TransitionExecutedEvent ->
                 SessionStatus.ACTIVE

core/sessions/src/test/kotlin/com/correx/core/sessions/DefaultSessionReducerTest.kt

@@ -57,6 +57,19 @@ class DefaultSessionReducerTest {
         assertNull(initialState.boundProfile)
     }
 
+    @Test
+    fun `WorkflowFailedEvent flips session status to FAILED`() {
+        val event = stored(
+            com.correx.core.events.events.WorkflowFailedEvent(
+                sessionId = sessionId,
+                stageId = com.correx.core.events.types.StageId("define_styling_tokens"),
+                reason = "did not produce declared artifacts",
+                retryExhausted = true,
+            ),
+        )
+        assertEquals(SessionStatus.FAILED, reducer.reduce(initialState, event).status)
+    }
+
     @Test
     fun `unrelated event leaves boundProfile unchanged`() {
         val state = initialState.copy(