feat(v0.4.1): make the Settlement Contract honest end-to-end

Patches each link of the closed-loop chain (world-truth -> invariant ->
dispatch -> worldDelta -> milestone) so the contract can no longer advance
on a lie or stall on an unreachable milestone, and surfaces the result on
the monitor.

- Unblock M6_lighting: add gather.coal producer (mirrors gather.stone,
  strict expectGain), register it, add the skill-graph node, and make
  curriculum.shelter.torch two-step (gather coal -> craft torch). craft.torch
  needed coal but no skill produced it, so the contract pinned on M6 forever
  and starved M7/M8/M9. One curriculum edit fixes both rails.
- M8 no longer falsely satisfied: build-shelter records locations.shelter
  only on real progress (setLocation moved below the no_progress guard).
- M2_bed made monotonic: sleepInBed writes locations.bed when the bot places
  its own bed, so M2 stays met after the carried bed item is consumed.
- Observability: new ink-free tui/format.js helper renders per-tick
  state / firing rail / active skill / blocked prerequisite / stall reason
  in the monitor header (fields bot.js already computes but never showed).
- Harden the valid-skill-id guardrail: skillRegistryPrompt preserves the
  "NEVER invent" footer when truncating (a growing registry was dropping it),
  and fix the stale "tech-tree > autonomous" reflex chain in the escalation
  prompt.

Tests: 494/494 passing; new build-shelter / invariants / format suites plus
skill-graph, curriculum, skill-registry cases. lint-patch clean. Deferred
audit findings recorded in plans/v0.4.0-vnext.md (local).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

runtime/curriculum.test.js

@@ -141,6 +141,28 @@ test("food.basic satisfied by high food bar even without food item", () => {
 	assert.equal(got.milestone.id, "storage.chest");
 });
 
+test("shelter.torch suggests gather.coal when no coal on hand (closes the M6 dead-end)", () => {
+	const inv = {
+		wooden_axe: 1, wooden_pickaxe: 1, wooden_sword: 1,
+		stone_axe: 1, stone_pickaxe: 1, stone_sword: 1, furnace: 1,
+		red_bed: 1, bread: 2,
+	};
+	const got = nextMilestone(snap(inv, { food: 20, locations: { chest: { x: 1, y: 64, z: 0 } } }));
+	assert.equal(got.milestone.id, "shelter.torch");
+	assert.equal(got.plan.skillId, "gather.coal");
+});
+
+test("shelter.torch suggests craft.torch once coal is on hand", () => {
+	const inv = {
+		wooden_axe: 1, wooden_pickaxe: 1, wooden_sword: 1,
+		stone_axe: 1, stone_pickaxe: 1, stone_sword: 1, furnace: 1,
+		red_bed: 1, bread: 2, coal: 1,
+	};
+	const got = nextMilestone(snap(inv, { food: 20, locations: { chest: { x: 1, y: 64, z: 0 } } }));
+	assert.equal(got.milestone.id, "shelter.torch");
+	assert.equal(got.plan.skillId, "craft.torch");
+});
+
 test("all done → null", () => {
 	const inv = {
 		oak_log: 16, oak_planks: 8, stick: 8,