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.js

@@ -31,6 +31,7 @@ export const SKILL_GRAPH = Object.freeze({
 	"gather.logs": { requires: [], produces: ["logs"] },
 	"gather.wool": { requires: [], produces: ["wool"] },
 	"gather.stone": { requires: [{ tool: "pickaxe" }], produces: ["cobblestone"] },
+	"gather.coal": { requires: [{ tool: "pickaxe" }], produces: ["coal"] },
 	"craft.planks": { requires: [{ item: "logs", min: 1 }], produces: ["planks"] },
 	"craft.sticks": { requires: [{ item: "planks", min: 2 }], produces: ["stick"] },
 	"craft.wooden-axe": { requires: [{ item: "planks", min: 3 }, { item: "stick", min: 2 }], produces: ["wooden_axe"] },