fix: add dist-check guard + List<T> type parsing + state machine examples

- check-dist.sh: Prevents DIST DESYNC by verifying all dist/*.js files
  are newer than their src/*.ts sources. Fails build if stale.
- Makefile: Standard build targets (build/check-dist/test/recompile/clean)
- src/index.ts: Integrated dist freshness check before compilation
- src/parser.ts: Added List<T> type parsing alongside existing Set<T>/Map<K,V>
  (e.g., 'log: List<LogEntry>' now parses as { type: 'list', elementType })
- examples/: Restored v0.3 state machine specs (TigerBeetleLedger,
  AccountLedger, ToggleSwitch, TwoPhaseCommit)
- DIST DESYNC is a known recurring anti-pattern — this guard prevents it

Tests: 39/41 pass (2 pre-existing E2E WASM failures due to missing wabt)

compiler/dist/index.js

@@ -8,7 +8,20 @@ import { generateSPDX } from './generators/spdx.js';
 import { generateTypeScriptStateMachine } from './generators/typescript-state-machine.js';
 import { generateWASM } from './generators/wasm.js';
 import fs from 'fs';
+import path from 'path';
 async function main() {
+    // Guard: check that dist is not stale before compiling
+    const checkScript = path.join(path.dirname(new URL(import.meta.url).pathname), '..', 'check-dist.sh');
+    if (fs.existsSync(checkScript)) {
+        try {
+            const { execSync } = await import('child_process');
+            execSync(`bash "${checkScript}"`, { stdio: 'inherit' });
+        }
+        catch {
+            console.error('\n❌ Cannot compile with stale dist. Rebuild first.');
+            process.exit(1);
+        }
+    }
     const argv = await yargs(hideBin(process.argv))
         .command('$0 <file>', 'Compile a SpeckDL specification', (yargsCmd) => {
         return yargsCmd