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/goal/skill-graph.test.js

@@ -41,6 +41,24 @@ test("unknown skill is treated as runnable (known:false)", () => {
 	assert.equal(r.known, false);
 });
 
+test("gather.coal needs a pickaxe and produces coal (closes the M6 dead-end)", () => {
+	assert.equal(canRun("gather.coal", world({})), false);
+	assert.equal(canRun("gather.coal", world({ wooden_pickaxe: 1 })), true);
+	assert.equal(canRun("gather.coal", world({ stone_pickaxe: 1 })), true);
+});
+
+test("craft.torch is blocked without coal but runnable once coal is gathered", () => {
+	assert.equal(canRun("craft.torch", world({ stick: 1 })), false);
+	assert.equal(canRun("craft.torch", world({ stick: 1, coal: 1 })), true);
+	// charcoal counts as coal (semantic group)
+	assert.equal(canRun("craft.torch", world({ stick: 1, charcoal: 1 })), true);
+});
+
+test("runnableFrontier includes gather.coal once a pickaxe is held", () => {
+	assert.ok(!runnableFrontier(world()).includes("gather.coal"));
+	assert.ok(runnableFrontier(world({ wooden_pickaxe: 1 })).includes("gather.coal"));
+});
+
 test("axe matcher excludes pickaxe", () => {
 	assert.equal(_internal.TOOL.axe("wooden_axe"), true);
 	assert.equal(_internal.TOOL.axe("wooden_pickaxe"), false);