feat(recovery): failure-ticket routing + review-gate RECOVER + return-to-sender

Retry-agency invariant: a stage may only retry a gate it has the capability
to change. A write-less stage failing a build/contract/static gate (e.g.
freestyle final_verification with allowedTools=[shell]) can never fix it, so
retrying in place is futile until the budget drains (Vikunja #41).

Instead: open a FailureTicketOpenedEvent (category + requiredCapability derived
deterministically from the gate id, no LLM) and route to a recovery stage that
holds the capability, bounded by a small per-stage route budget.

- Slice 2: SalvageDecision.RECOVER (ternary CONTINUE/RECOVER/FAIL) lets the
  review-gate salvage judge hand off to recovery. Shared routeToRecovery()
  unifies the deterministic agency guard and the judge on one destination;
  decideGateExhaustion now returns StepResult?.
- Return-to-sender: recovery's exit is dynamic (recoveryReturnMove) — it goes
  back to the exact ticket-origin stage to re-run its gate, so a write-less
  gate anywhere in the graph is handled without skipping intervening stages.
  The synthesized recovery->terminal edge is now only a no-ticket fallback.
- Freestyle wiring: ExecutionPlanCompiler injectRecovery flag (Main passes
  true) synthesizes a write-capable recovery stage; ticket evidence reaches it
  via buildRecoveryTicketEntry.
- Read-only tools always present: StageConfig.effectiveAllowedTools adds
  file_read/list_dir to any tool-granting stage (fixes the verifier reaching
  for `shell ls -R` to inspect the tree).

Tests: RecoveryRoutingTest (deterministic gate, no static return edge — proves
dynamic return) + GateRetryBudgetExhaustionTest RECOVER case + two compiler
tests. All green; detekt clean.

apps/server/src/main/kotlin/com/correx/apps/server/Main.kt

@@ -371,7 +371,11 @@ fun main() {
     // Plan-compile gate: wrap the ExecutionPlanCompiler as a post-stage check so a compile-invalid
     // architect plan is handed back through the retry-feedback loop instead of parking the session in
     // ACTIVE (post-planning compile dead-end). Returns null on success, the compiler message on failure.
-    val planCompiler = ExecutionPlanCompiler(artifactKindRegistry, toolRegistry.all().map { it.name }.toSet())
+    val planCompiler = ExecutionPlanCompiler(
+        artifactKindRegistry,
+        toolRegistry.all().map { it.name }.toSet(),
+        injectRecovery = true,
+    )
     val orchestrator = DefaultSessionOrchestrator(
         repositories = repositories,
         engines = engines.copy(