fix(newos4): help names the owner of an undocumented command; loop lessons leave /skills

Two board items plus the context-window close-out.

- MAINT-019 (module-system.js): `help <cmd>` answered "No help available for X" for a command
  that is registered but has no help line, which reads as if the command does not exist. It now
  says "X — registered by <Module>, which publishes no help line for it. Try: help". A command
  that genuinely does not exist still gets the old message.
- MAINT-020 (module-aiassist.js): auto-generated loop lessons were written into /skills with
  their own index entries, so `skill list` filled up with system noise. Lessons now live in
  /lessons with /lessons/index.json; the reader still falls back to legacy loop-lesson-* entries
  in /skills for one release, and the one-time migration deletes them from the skills index.

Verification: test-help-and-lessons.js (10 asserts, includes a lint-style guard that no lesson is
written into /skills). Suite 14/14 files green; maintain --fix "node tests 14/14 pass",
"help coverage 362/362". Live on v4.6.108: `help agent-register` -> "registered by
AgentRegistryModule, which publishes no help line for it"; `help a2a-prune` unchanged;
`help nope-not-real` still "No help available".

MAINT-001 close-out (no code change here): history is capped at 20 messages with a "[context trim]"
marker (first trim at turn 11 in a 60-turn probe), token compression took 80 msgs/8080 tok to
17/2625, and since v4.6.107 one turn's tool bodies are clipped to 6 000 chars each and elided past
24 000 with the newest 4 kept verbatim. Residual, recorded on the board: maxContextTokens is never
sent to the server as num_ctx, so the real window is whatever the endpoint defaults to.

MAINT-018 close-out: not reproducible. Live probes on v4.6.107/108 — `sed -n '1,3p' /probe.txt`
prints lines 1-3, `sed -n "2,4p"` prints 2-4, `grep 'line4'` matches, and the same commands inside
`script /q.sh` print correctly. The "Command not found: for;" symptom belongs to the line-by-line
script runner, which is MAINT-021 and stays open.

1 files changed, 75 insertions, 0 deletions

diff --git a/modules/test/test-help-and-lessons.js b/modules/test/test-help-and-lessons.js
new file mode 100644
index 0000000..c4eb5ae
--- /dev/null
+++ b/modules/test/test-help-and-lessons.js
@@ -0,0 +1,75 @@
+// modules/test/test-help-and-lessons.js — run: node
+// MAINT-019: `help <cmd>` must not answer "No help available" for a command that exists.
+// MAINT-020: loop lessons must be written to /lessons, never into /skills.
+const fsMod = require('fs'), path = require('path');
+const ROOT = path.join(__dirname, '..');
+const store = {};
+global.localStorage = { getItem: k => (k in store ? store[k] : null), setItem: (k, v) => { store[k] = String(v); }, removeItem: k => { delete store[k]; } };
+global.indexedDB = { open() { throw new Error('no idb'); }, deleteDatabase() { throw new Error('no idb'); } };
+global.window = global;
+
+const SystemModule = new Function(fsMod.readFileSync(path.join(ROOT, 'core', 'module-system.js'), 'utf8') + '\nreturn SystemModule;')();
+
+let fails = 0, passes = 0;
+function ok(name, cond, detail) {
+    if (cond) { passes++; return; }
+    fails++;
+    console.log('FAIL ' + name + (detail ? ' — ' + detail : ''));
+}
+
+function mkHelp(commands, help) {
+    const out = [];
+    const sys = Object.create(SystemModule.prototype);
+    sys.terminal = {
+        print: (m, t) => out.push({ text: String(m), type: t || '' }),
+        log: () => {},
+        moduleManager: {
+            getAllCommands: () => commands,
+            getAllHelp: () => help,
+        },
+    };
+    return { sys, out };
+}
+const text = out => out.map(o => o.text).join(' | ');
+
+// A. a documented command prints its help line
+{
+    const { sys, out } = mkHelp({ ls: 'FileSystemModule' }, { ls: 'ls [path] — List files' });
+    sys.handleHelp(['ls']);
+    ok('A1 documented command shows its help', /ls \[path\]/.test(text(out)), text(out));
+}
+
+// B. an undocumented but registered command names its owner instead of denying it exists
+{
+    const { sys, out } = mkHelp({ 'agent-register': 'AgentRegistryModule' }, {});
+    sys.handleHelp(['agent-register']);
+    const t = text(out);
+    ok('B1 no "No help available" for a registered command', !/No help available/.test(t), t);
+    ok('B2 the owning module is named', /AgentRegistryModule/.test(t), t);
+    ok('B3 it still says there is no help line', /no help line/i.test(t), t);
+}
+
+// C. a command that really does not exist still says so
+{
+    const { sys, out } = mkHelp({ ls: 'FileSystemModule' }, { ls: 'ls — List' });
+    sys.handleHelp(['definitely-not-a-command']);
+    ok('C1 unknown command still reports no help', /No help available/.test(text(out)), text(out));
+}
+
+// D. MAINT-020: no lesson is written into /skills, and /lessons is used instead
+{
+    const src = fsMod.readFileSync(path.join(ROOT, 'core', 'module-aiassist.js'), 'utf8');
+    const writesSkils = /writeFile\(\s*'\/skills\/'\s*\+\s*skillName/.test(src);
+    ok('D1 no lesson file is written into /skills', !writesSkils);
+    ok('D2 lesson files are written into /lessons', /writeFile\(\s*'\/lessons\/'\s*\+\s*skillName/.test(src));
+    ok('D3 the lessons index is written to /lessons', /fsWriteJSON\(\s*'\/lessons\/index\.json'/.test(src));
+    ok('D4 the reader still handles legacy /skills lessons', /fs\.readFile\('\/skills\/' \+ recentLessons\[li\] \+ '\.md'\)/.test(src));
+    ok('D5 legacy lessons are cleaned out of the skills index once', /indexOf\('loop-lesson-'\) === 0/.test(src));
+}
+
+if (fails === 0) {
+    console.log('test-help-and-lessons: ' + passes + ' passed, 0 failed');
+} else {
+    console.log('test-help-and-lessons: ' + passes + ' passed, ' + fails + ' FAILED');
+    process.exit(1);
+}