feat(agent): plan-first gate, iterative follow-ups, reasoning persistence

P1 plan-first: run handler refuses without propose_plan (structural gate,
not SOUL.md prose). Plan window decoupled from set_goal — config_mutation
auto-run only on operator approval (assent window). Closes the approval-free
config_mutation hole confirmed in session d0d562e0.

P2 iteration: reopenSession flips terminal→executing, marks prior plan steps
replaced, clears outcome. proposePlan excludes replaced from in-flight check,
bumps generation. A follow-up on a completed session starts a new sub-task
with a fresh plan — no more errPlanInFlight dead end.

P3 reasoning: accumulate per-iteration text into the persisted row instead
of overwriting with the last text event. Reload shows intermediate thinking,
not just the final summary.

P4 read-only allowlist: add find, tree, locate, systemctl list-timers/
list-unit-files/show, timedatectl, hostnamectl, systemd-analyze, rclone
ls/lsl/md5sum/check/cryptcheck. Fixes the find misclassification from
d0d562e0.

P5 eval harness: new assertion kinds (proposes_plan, plan_before_run,
plan_generations), multi-turn followups, fetch /sessions/{id}/plan. Four
manifests under evals/.

P6 SOUL.md: strip degenerate-case carve-out, add ITERATE step, update
set_goal guidance.

VERSION 0.6.0 → 0.7.0

cmd/nomos/tasks.go

@@ -176,12 +176,16 @@ func (a *agent) handleTaskTool(ctx context.Context, sessionID, name string, args
 		if err := a.store.setGoal(ctx, sessionID, goal); err != nil {
 			return fmt.Sprintf("error setting goal: %v", err), true
 		}
-		// Open the plan window immediately — the goal IS the start of a
-		// plan. Config_mutation commands in this session auto-execute
-		// without per-action approval. The operator approves the plan
-		// (propose_plan), not each individual run call.
-		a.store.openPlanWindow(ctx, sessionID)
-		return "Goal set: " + goal + ". NEXT: pre-plan (read-only tools only — search_knowledge, get_entity, list_lxcs, get_relations). Then propose_plan. Do not call run.", true
+		// P1: the plan window is NOT opened here. Opening it on set_goal
+		// meant any config_mutation `run` auto-executed with zero operator
+		// approval, before a plan was even proposed (let alone approved) —
+		// a safety regression confirmed live in session d0d562e0. The
+		// window is now opened only when the operator approves a plan
+		// (chat-assent grant or explicit approval in agent.go), which is
+		// what the SOUL.md "approve the plan, not each step" model actually
+		// describes. set_goal records the goal + flips status to executing
+		// and nothing more.
+		return "Goal set: " + goal + ". NEXT: pre-plan with read-only tools (search_knowledge, get_entity, list_lxcs, get_relations), then propose_plan (mandatory — even read-only tasks need a one-step plan; the run handler refuses without one). Do not call run before propose_plan.", true
 
 	case "propose_plan":
 		raw, _ := args["steps"].([]any)
@@ -237,7 +241,7 @@ func (a *agent) handleTaskTool(ctx context.Context, sessionID, name string, args
 				// the "plan added twice" sidebar drift the operator
 				// reported: instead of appending (which duplicated) or
 				// wiping (which lost progress), we refuse and direct.
-				return "Plan already in flight — refusing duplicate proposal. Steps exist and at least one has started (running/done/...). To advance: call update_plan_step(seq=K, status=\"running\") then run(...) for step K's target, then update_plan_step(seq=K, status=\"done\"). Do NOT call propose_plan again. Re-propose only if the operator explicitly asks you to revise the whole plan, and say so in your reply before calling it.", true
+				return "Plan already in flight — refusing duplicate proposal. Steps exist and at least one has started (running/done/...). To advance: call update_plan_step(seq=K, status=\"running\") then run(...) for step K's target, then update_plan_step(seq=K, status=\"done\"). Do not call propose_plan again. Re-propose only if the operator explicitly asks you to revise the whole plan (the session is reopened on a follow-up — prior steps are marked `replaced` and a fresh generation is started), and say so in your reply before calling it.", true
 			}
 			return fmt.Sprintf("error proposing plan: %v", err), true
 		}