v0.21.0: agent reliability overhaul — plan integrity, target validation, observability pipelines, learning loop

P0 — stop the bleeding:
- prevent premature complete_task(success) when goal involves reachability
- validate run targets: block host-only commands (qm/pct/pvesh) on LXC/VM
- bump MCP client timeout 30s→120s to stop 'context deadline exceeded'

P1 — fix the plan system:
- add replaced_reason column to session_plan_steps (migration 030)
- track WHY steps are replaced (wrong_diagnosis/scope_change/superseded/etc)
- force fresh propose_plan on session resume (reopenSession marks old plan)

P2 — cognitive guardrails:
- SOUL.md scope-gate rule: ask before chasing unrelated subsystems
- auto-upsert knowledge entry on every session close

P3 — observability (all were empty/NULL):
- populate agent_activity.token_count from LLM usage (was always NULL)
- populate nomos_plan_executions linking executions to sessions
- write plan_completion_rate metric on task close

P4 — learning loop (all were empty/NULL):
- auto-classify every run call → classifications table (was 0 rows)
- auto-feedback on session close (was 0 rows)

cmd/nomos/store_test.go

@@ -192,7 +192,7 @@ func TestProposePlan_RefuseInFlight(t *testing.T) {
 	}
 
 	// Mark step 1 as started.
-	if err := s.updatePlanStep(ctx, sess.ID, 1, "running", ""); err != nil {
+	if err := s.updatePlanStep(ctx, sess.ID, 1, "running", "", ""); err != nil {
 		t.Fatalf("updatePlanStep: %v", err)
 	}
 
@@ -288,10 +288,10 @@ func TestUpdatePlanStep_GenerationRelative(t *testing.T) {
 
 	// The model addresses the new plan with 1-based seq. seq=1 must hit
 	// gen-2 "C", leaving gen-1 "A" (replaced) untouched.
-	if err := s.updatePlanStep(ctx, sess.ID, 1, "running", ""); err != nil {
+	if err := s.updatePlanStep(ctx, sess.ID, 1, "running", "", ""); err != nil {
 		t.Fatalf("updatePlanStep(seq=1, running): %v", err)
 	}
-	if err := s.updatePlanStep(ctx, sess.ID, 1, "done", ""); err != nil {
+	if err := s.updatePlanStep(ctx, sess.ID, 1, "done", "", ""); err != nil {
 		t.Fatalf("updatePlanStep(seq=1, done): %v", err)
 	}
 
@@ -319,7 +319,7 @@ func TestUpdatePlanStep_GenerationRelative(t *testing.T) {
 	}
 
 	// Out-of-range seq must be refused (no current-gen step there).
-	if err := s.updatePlanStep(ctx, sess.ID, 99, "running", ""); !errors.Is(err, errPlanStepNotFound) {
+	if err := s.updatePlanStep(ctx, sess.ID, 99, "running", "", ""); !errors.Is(err, errPlanStepNotFound) {
 		t.Fatalf("updatePlanStep(seq=99) err = %v, want errPlanStepNotFound", err)
 	}
 }
@@ -341,7 +341,7 @@ func TestCompleteTask_AutoCloseEmitsEvents(t *testing.T) {
 		t.Fatalf("proposePlan: %v", err)
 	}
 	// A is running, B still pending at completion time.
-	if err := s.updatePlanStep(ctx, sess.ID, 1, "running", ""); err != nil {
+	if err := s.updatePlanStep(ctx, sess.ID, 1, "running", "", ""); err != nil {
 		t.Fatalf("updatePlanStep(1, running): %v", err)
 	}
 	if err := s.completeTask(ctx, sess.ID, "success", "done"); err != nil {
@@ -397,7 +397,7 @@ func TestHadDiscoveryAndWriteback(t *testing.T) {
 
 	// A `run` call (discovery) — should set hadDiscovery, not hadEntityWriteback.
 	agentID := uuid.New()
-	s.logActivity(ctx, agentID, sess.ID, "run", nil, "", "uptime output", 100, true, "corr-1")
+	s.logActivity(ctx, agentID, sess.ID, "run", nil, "", "uptime output", 100, true, "corr-1", 0)
 	if !s.hadDiscovery(ctx, sess.ID) {
 		t.Fatal("hadDiscovery = false after a successful run call, want true")
 	}
@@ -410,7 +410,7 @@ func TestHadDiscoveryAndWriteback(t *testing.T) {
 	if err != nil {
 		t.Fatalf("createSession: %v", err)
 	}
-	s.logActivity(ctx, agentID, sess2.ID, "run", nil, "", "ssh timeout", 100, false, "corr-2")
+	s.logActivity(ctx, agentID, sess2.ID, "run", nil, "", "ssh timeout", 100, false, "corr-2", 0)
 	if s.hadDiscovery(ctx, sess2.ID) {
 		t.Fatal("hadDiscovery = true after a failed run call, want false (no facts learned)")
 	}
@@ -420,7 +420,7 @@ func TestHadDiscoveryAndWriteback(t *testing.T) {
 	if err != nil {
 		t.Fatalf("createSession: %v", err)
 	}
-	s.logActivity(ctx, agentID, sess3.ID, "get_entity", nil, "", "entity row", 10, true, "corr-3")
+	s.logActivity(ctx, agentID, sess3.ID, "get_entity", nil, "", "entity row", 10, true, "corr-3", 0)
 	if s.hadDiscovery(ctx, sess3.ID) {
 		t.Fatal("hadDiscovery = true after get_entity, want false (DB lookups are not discovery)")
 	}
@@ -430,12 +430,12 @@ func TestHadDiscoveryAndWriteback(t *testing.T) {
 	if err != nil {
 		t.Fatalf("createSession: %v", err)
 	}
-	s.logActivity(ctx, agentID, sess4.ID, "update_entity_attributes", nil, "", "ok", 10, true, "corr-4")
+	s.logActivity(ctx, agentID, sess4.ID, "update_entity_attributes", nil, "", "ok", 10, true, "corr-4", 0)
 	if !s.hadEntityWriteback(ctx, sess4.ID) {
 		t.Fatal("hadEntityWriteback = false after update_entity_attributes, want true")
 	}
 	// And the discovery+writeback combination (the conv3 scenario).
-	s.logActivity(ctx, agentID, sess4.ID, "run", nil, "", "apt-get update output", 100, true, "corr-5")
+	s.logActivity(ctx, agentID, sess4.ID, "run", nil, "", "apt-get update output", 100, true, "corr-5", 0)
 	if !s.hadDiscovery(ctx, sess4.ID) {
 		t.Fatal("hadDiscovery = false after run+writeback, want true")
 	}