security: add the capability and policy layer as the only path to action

Phase 12 (ADR-0005). Capabilities are registered in code with parameter
schemas, risk classes and default effects; sudo_shell and delete_database
are locked to DENY and cannot be relaxed. Policies are scoped globally or
per mind with capability, target glob, action kind and optional hour
window; evaluation is deterministic, most specific wins, and ties go to
the stricter effect. Invoke is the single entry point: it refuses
dreaming and replay contexts, validates parameters (unknown keys, non
http URLs and path traversal rejected), evaluates policy and session
grants, hashes the exact request and records a policy_decision event.
ALLOW executes with timeout and panic isolation and turns textual output
into a tool-trust observation; ASK creates an approval request bound to
the hash with an alert notification; DENY is counted and recorded.

Operators approve once, approve for a time-boxed session grant, deny
with a note, or modify parameters (re-validated, re-hashed, original
kept in the append-only decision log). The self-model's capability list
is recomputed from effective policy on start and on every policy change.
The act process maps fetch requests to http.fetch and the action handler
invokes through the layer; replies report capabilities and outcomes.

Policy matrix and approval centre pages, dashboard count, API, CLI
(approvals, policy, invoke) and docs/capabilities.md.

internal/cognition/respond.go

@@ -200,12 +200,24 @@ func (h Handlers) buildIntent(ctx context.Context, c *brain.Cycle, a conversatio
 		}
 	case "request":
 		in.Kind = "decline"
-		caps := c.State.SelfModel.Capabilities
-		if len(caps) == 0 {
+		var usable []string
+		for _, cap := range c.State.SelfModel.Capabilities {
+			if cap.Policy == "allow" || cap.Policy == "ask" {
+				usable = append(usable, cap.Name+" ("+cap.Policy+")")
+			}
+		}
+		if len(usable) == 0 {
 			in.Summary = "Explain honestly that no external capabilities are granted, so the request cannot be carried out; offer what is known instead."
 			in.Points = append(in.Points, "I have no capabilities granted to act on external systems.")
 		} else {
-			in.Summary = "Explain which capabilities exist and that actions require policy approval."
+			in.Kind = "acknowledge"
+			in.Summary = "Say which capabilities could apply and that any action goes through policy; if one was proposed this cycle its status is in working memory."
+			in.Points = append(in.Points, "Capabilities I may use: "+strings.Join(usable, ", ")+".")
+			for _, it := range c.Runtime.Workspace().WorkingMemory {
+				if strings.HasPrefix(it.Key, "action:") {
+					in.Points = append(in.Points, "Action status: "+it.Content)
+				}
+			}
 		}
 		h.addKnowledge(ctx, c, &in, topic)
 	case "introspection":