fix(weak-model-gates): stop three gates from stalling weak stage models

Diagnosed from session 508c8d58 (frontend freestyle run, WorkflowFailed):
three independent weak-model-hostile gates, none a model-capability problem.

- shell: split a collapsed single-string command line (["npm create vite …"])
  into tokens instead of rejecting it as a "collapsed array". The model
  reliably re-emits this shape; rejecting looped bootstrap_frontend until
  stage_loop_break. JSON-escape mangles (quotes/commas in argv[0]) stay rejected.
- recovery: a stage_loop_break route now gets a "Stuck-loop ticket", not the
  "Contract arbitration ticket". The arbitration prompt told the model to read
  and reconcile "the files named below" — but a tool-syntax loop names zero
  files, sending the recovery agent grepping the repo for 40+ turns until the
  repair ladder exhausted.
- plan lint: H3 (unreferenced_prompt_artifact) demoted from hard failure to
  soft finding, and seeds excluded from it. It word-matches artifact IDs in
  free prose and cannot tell a forgotten dep from a descriptive mention, so as
  a hard gate it burned architect retries on words it couldn't reword away
  (analysis/dod). Hard tier is now deterministic graph facts only (H1/H2).

Tests: ShellToolTest, PlanLinterTest, RecoveryRoutingTest green; detekt clean.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015Ly2mMnt9TCZbvhcC1JfuV

core/kernel/src/main/kotlin/com/correx/core/kernel/orchestration/ContextFeedback.kt

@@ -82,10 +82,24 @@ fun buildRecoveryTicketEntry(events: List<StoredEvent>, stageId: StageId): Conte
     val ticket = events
         .mapNotNull { it.payload as? FailureTicketOpenedEvent }
         .lastOrNull { it.routeTo == stageId } ?: return null
-    val content = if (ticket.escalated) {
+    val intent = events.mapNotNull { it.payload as? InitialIntentEvent }.lastOrNull()?.intent
+    val content = if (ticket.gate == STAGE_LOOP_BREAK_GATE) {
+        // A stuck-loop route is NOT a cross-file contract dispute — the gate output names no files, it
+        // is the SAME action (often a malformed tool call) repeated until the loop-break tripped. The
+        // arbitration prompt (read/reconcile the named files) sends the model hunting for files that
+        // don't exist. Tell it plainly: the last action is futile, take a materially different one.
+        "## Stuck-loop ticket\n" +
+            "Stage '${ticket.stageId.value}' repeated the SAME failing action until it tripped the " +
+            "'${ticket.gate}' gate. Retrying that action again is futile — it will fail identically. The " +
+            "exact failure is below; it is a single stuck step, NOT a dispute between files, so do not go " +
+            "looking for files to reconcile. If it is a malformed tool call, fix the call's shape and " +
+            "continue the task; otherwise take a materially different route to the same goal. Serve the " +
+            "intent" + (intent?.let { " below" } ?: "") + ", then control returns to verification." +
+            (intent?.let { "\n### Intent (authoritative)\n$it" } ?: "") +
+            "\n### Gate output (the failing action)\n${ticket.evidence}"
+    } else if (ticket.escalated) {
         // Tier 2: the owner loop couldn't settle it — a cross-file contract dispute. The arbiter holds
         // the intent and reconciles ALL sides in one pass.
-        val intent = events.mapNotNull { it.payload as? InitialIntentEvent }.lastOrNull()?.intent
         "## Contract arbitration ticket\n" +
             "Stage '${ticket.stageId.value}' keeps failing the '${ticket.gate}' gate even after the " +
             "file owners repaired their own layers — so this is NOT a bug in one file. The files named " +