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.

6 files changed, 151 insertions, 38 deletions

diff --git a/main.html b/main.html
index cf782e4..79c77cd 100644
--- a/main.html
+++ b/main.html
@@ -1349,13 +1349,13 @@
     </script>
 
     <!-- v4.5.63: A2A scratchpad fixes + agent-register arg fix -->
-<script src="modules/core/core-bundle.js?v=v4.6.107"></script>
+<script src="modules/core/core-bundle.js?v=v4.6.108"></script>
 
     <!-- Async dependency-ordered module loader now only initializes terminal and loads optional ext modules -->
-<script src="modules/core/module-loader.js?v=v4.6.107"></script>
+<script src="modules/core/module-loader.js?v=v4.6.108"></script>
 
     <!-- Critical ext bundle loads AFTER webx11 exists so registerModule calls work -->
-<script src="modules/ext/critical-ext-bundle.js?v=v4.6.107"></script>
+<script src="modules/ext/critical-ext-bundle.js?v=v4.6.108"></script>
 
 <script>
 // ═══ ONE TRUE VERSION SOURCE ═══
diff --git a/modules/core/core-bundle.js b/modules/core/core-bundle.js
index c06af5f..d7d9d61 100644
--- a/modules/core/core-bundle.js
+++ b/modules/core/core-bundle.js
@@ -6431,7 +6431,11 @@ Only output XML function calls for tool tasks. If no tool is needed, answer norm
                         if (helpEntry) {
                             this.terminal.print(helpEntry, 'info');
                         } else {
-                            this.terminal.print(`No help available for ${cmd}`, 'warning');
+                            // MAINT-019: a registered command with no help line answered "No help
+                            // available", which reads as if the command does not exist. Name the
+                            // module that owns it so the user knows where to look.
+                            const owner = allCommands[cmd];
+                            this.terminal.print(`${cmd} — registered by ${owner}, which publishes no help line for it. Try: help`, 'warning');
                         }
                     } else {
                         this.terminal.print(`No help available for ${cmd}`, 'warning');
@@ -10045,13 +10049,21 @@ buildSystemPrompt() {
                 try {
                     var fs = this.terminal.fs;
                     if (fs) {
-                        var index = fs.fsReadJSON('/skills/index.json') || {};
-                        var lessonKeys = Object.keys(index).filter(function(k) { return k.indexOf('loop-lesson-') === 0; });
+                        // MAINT-020: lessons live in /lessons, not in /skills — writing them into
+                        // the skills directory made auto-generated lessons show up as skills.
+                        var index = fs.fsReadJSON('/lessons/index.json') || {};
+                        var lessonKeys = Object.keys(index);
+                        if (lessonKeys.length === 0) {
+                            // one-release fallback for lessons written by older builds
+                            var legacy = fs.fsReadJSON('/skills/index.json') || {};
+                            lessonKeys = Object.keys(legacy).filter(function(k) { return k.indexOf('loop-lesson-') === 0; });
+                        }
                         if (lessonKeys.length > 0) {
                             var recentLessons = lessonKeys.sort().slice(-3);
                             var lessonTexts = [];
                             for (var li = 0; li < recentLessons.length; li++) {
-                                var lc = fs.readFile('/skills/' + recentLessons[li] + '.md');
+                                var lc = fs.readFile('/lessons/' + recentLessons[li] + '.md')
+                                    || fs.readFile('/skills/' + recentLessons[li] + '.md');
                                 if (lc) {
                                     var excerpt = lc.substring(0, 300);
                                     lessonTexts.push('[Lesson: ' + recentLessons[li] + '] ' + excerpt);
@@ -13187,23 +13199,30 @@ buildSystemPrompt() {
                 var suggestion = suggestions.join('\n');
                 try {
                     var fs = this.terminal.fs;
-                    var index = fs.fsReadJSON('/skills/index.json') || {};
-                    var autoSkills = Object.entries(index).filter(function(e) { return (e[1].tags || []).indexOf('auto-improvement') !== -1; });
-                    // One-time cleanup: remove all existing loop-lesson files on first run
+                    // MAINT-020: lessons are kept in /lessons with their own index; /skills is
+                    // reserved for real skills the user or the agent creates deliberately.
+                    try { fs.mkdirRecursive('/lessons'); } catch (ex) {}
+                    var index = fs.fsReadJSON('/lessons/index.json') || {};
+                    var autoSkills = Object.entries(index);
+                    // One-time migration: earlier builds wrote loop-lesson-* into /skills.
                     if (!this._loopLessonCleaned) {
                         this._loopLessonCleaned = true;
-                        autoSkills.forEach(function(e) {
-                            try { fs.unlink('/skills/' + e[0] + '.md'); } catch (ex) {}
-                            delete index[e[0]];
-                        });
-                        autoSkills = [];
+                        try {
+                            var sIdx = fs.fsReadJSON('/skills/index.json') || {};
+                            Object.keys(sIdx).filter(function(k) { return k.indexOf('loop-lesson-') === 0; })
+                                .forEach(function(k) {
+                                    try { fs.unlink('/skills/' + k + '.md'); } catch (ex) {}
+                                    delete sIdx[k];
+                                });
+                            fs.fsWriteJSON('/skills/index.json', sIdx);
+                        } catch (ex) {}
                     }
                     // Age limit: remove lessons older than 24h
                     var now = Date.now();
                     autoSkills = autoSkills.filter(function(e) {
                         var created = new Date(e[1].created).getTime();
                         if (now - created > 86400000) {
-                            try { fs.unlink('/skills/' + e[0] + '.md'); } catch (ex) {}
+                            try { fs.unlink('/lessons/' + e[0] + '.md'); } catch (ex) {}
                             delete index[e[0]];
                             return false;
                         }
@@ -13215,17 +13234,17 @@ buildSystemPrompt() {
                     // FIFO rotation: if at cap, delete oldest before creating
                     if (!isDuplicate && autoSkills.length >= 3) {
                         var oldest = autoSkills[0];
-                        try { fs.unlink('/skills/' + oldest[0] + '.md'); } catch (ex) {}
+                        try { fs.unlink('/lessons/' + oldest[0] + '.md'); } catch (ex) {}
                         delete index[oldest[0]];
                         autoSkills.shift();
                     }
                     if (!isDuplicate) {
                         var skillName = 'loop-lesson-' + Date.now();
                         var content = '---\nname: ' + skillName + '\ndescription: Auto-saved from agent loop anomaly detection\ntags: [auto-improvement, agent-loop, auto]\ncategory: system\n---\n## Anomalies Detected\n\n' + JSON.stringify(anomalies, null, 2) + '\n\n## Suggestions\n\n' + suggestion + '\n\n## Context\n- Profile: ' + (this._activeLoopProfile ? this._activeLoopProfile.name : 'none') + '\n- Turns: ' + result.toolTurns + '\n- Tools used: ' + toolLog.map(function(t) { return t.name; }).join(', ');
-                        fs.mkdirRecursive('/skills');
-                        fs.writeFile('/skills/' + skillName + '.md', content);
+                        fs.mkdirRecursive('/lessons');
+                        fs.writeFile('/lessons/' + skillName + '.md', content);
                         index[skillName] = { name: skillName, description: 'Auto-saved loop lesson', tags: ['auto-improvement', 'agent-loop', 'auto'], category: 'system', created: new Date().toISOString(), updated: new Date().toISOString(), anomalyTypes: anomalyTypes };
-                        fs.fsWriteJSON('/skills/index.json', index);
+                        fs.fsWriteJSON('/lessons/index.json', index);
                     }
                 } catch (e) { /* VFS not available */ }
                 var msg = '💡 Self-improvement: ' + anomalies.length + ' anomaly(ies)';
diff --git a/modules/core/module-aiassist.js b/modules/core/module-aiassist.js
index 9965e6a..be5ebce 100644
--- a/modules/core/module-aiassist.js
+++ b/modules/core/module-aiassist.js
@@ -1530,13 +1530,21 @@ buildSystemPrompt() {
                 try {
                     var fs = this.terminal.fs;
                     if (fs) {
-                        var index = fs.fsReadJSON('/skills/index.json') || {};
-                        var lessonKeys = Object.keys(index).filter(function(k) { return k.indexOf('loop-lesson-') === 0; });
+                        // MAINT-020: lessons live in /lessons, not in /skills — writing them into
+                        // the skills directory made auto-generated lessons show up as skills.
+                        var index = fs.fsReadJSON('/lessons/index.json') || {};
+                        var lessonKeys = Object.keys(index);
+                        if (lessonKeys.length === 0) {
+                            // one-release fallback for lessons written by older builds
+                            var legacy = fs.fsReadJSON('/skills/index.json') || {};
+                            lessonKeys = Object.keys(legacy).filter(function(k) { return k.indexOf('loop-lesson-') === 0; });
+                        }
                         if (lessonKeys.length > 0) {
                             var recentLessons = lessonKeys.sort().slice(-3);
                             var lessonTexts = [];
                             for (var li = 0; li < recentLessons.length; li++) {
-                                var lc = fs.readFile('/skills/' + recentLessons[li] + '.md');
+                                var lc = fs.readFile('/lessons/' + recentLessons[li] + '.md')
+                                    || fs.readFile('/skills/' + recentLessons[li] + '.md');
                                 if (lc) {
                                     var excerpt = lc.substring(0, 300);
                                     lessonTexts.push('[Lesson: ' + recentLessons[li] + '] ' + excerpt);
@@ -4672,23 +4680,30 @@ buildSystemPrompt() {
                 var suggestion = suggestions.join('\n');
                 try {
                     var fs = this.terminal.fs;
-                    var index = fs.fsReadJSON('/skills/index.json') || {};
-                    var autoSkills = Object.entries(index).filter(function(e) { return (e[1].tags || []).indexOf('auto-improvement') !== -1; });
-                    // One-time cleanup: remove all existing loop-lesson files on first run
+                    // MAINT-020: lessons are kept in /lessons with their own index; /skills is
+                    // reserved for real skills the user or the agent creates deliberately.
+                    try { fs.mkdirRecursive('/lessons'); } catch (ex) {}
+                    var index = fs.fsReadJSON('/lessons/index.json') || {};
+                    var autoSkills = Object.entries(index);
+                    // One-time migration: earlier builds wrote loop-lesson-* into /skills.
                     if (!this._loopLessonCleaned) {
                         this._loopLessonCleaned = true;
-                        autoSkills.forEach(function(e) {
-                            try { fs.unlink('/skills/' + e[0] + '.md'); } catch (ex) {}
-                            delete index[e[0]];
-                        });
-                        autoSkills = [];
+                        try {
+                            var sIdx = fs.fsReadJSON('/skills/index.json') || {};
+                            Object.keys(sIdx).filter(function(k) { return k.indexOf('loop-lesson-') === 0; })
+                                .forEach(function(k) {
+                                    try { fs.unlink('/skills/' + k + '.md'); } catch (ex) {}
+                                    delete sIdx[k];
+                                });
+                            fs.fsWriteJSON('/skills/index.json', sIdx);
+                        } catch (ex) {}
                     }
                     // Age limit: remove lessons older than 24h
                     var now = Date.now();
                     autoSkills = autoSkills.filter(function(e) {
                         var created = new Date(e[1].created).getTime();
                         if (now - created > 86400000) {
-                            try { fs.unlink('/skills/' + e[0] + '.md'); } catch (ex) {}
+                            try { fs.unlink('/lessons/' + e[0] + '.md'); } catch (ex) {}
                             delete index[e[0]];
                             return false;
                         }
@@ -4700,17 +4715,17 @@ buildSystemPrompt() {
                     // FIFO rotation: if at cap, delete oldest before creating
                     if (!isDuplicate && autoSkills.length >= 3) {
                         var oldest = autoSkills[0];
-                        try { fs.unlink('/skills/' + oldest[0] + '.md'); } catch (ex) {}
+                        try { fs.unlink('/lessons/' + oldest[0] + '.md'); } catch (ex) {}
                         delete index[oldest[0]];
                         autoSkills.shift();
                     }
                     if (!isDuplicate) {
                         var skillName = 'loop-lesson-' + Date.now();
                         var content = '---\nname: ' + skillName + '\ndescription: Auto-saved from agent loop anomaly detection\ntags: [auto-improvement, agent-loop, auto]\ncategory: system\n---\n## Anomalies Detected\n\n' + JSON.stringify(anomalies, null, 2) + '\n\n## Suggestions\n\n' + suggestion + '\n\n## Context\n- Profile: ' + (this._activeLoopProfile ? this._activeLoopProfile.name : 'none') + '\n- Turns: ' + result.toolTurns + '\n- Tools used: ' + toolLog.map(function(t) { return t.name; }).join(', ');
-                        fs.mkdirRecursive('/skills');
-                        fs.writeFile('/skills/' + skillName + '.md', content);
+                        fs.mkdirRecursive('/lessons');
+                        fs.writeFile('/lessons/' + skillName + '.md', content);
                         index[skillName] = { name: skillName, description: 'Auto-saved loop lesson', tags: ['auto-improvement', 'agent-loop', 'auto'], category: 'system', created: new Date().toISOString(), updated: new Date().toISOString(), anomalyTypes: anomalyTypes };
-                        fs.fsWriteJSON('/skills/index.json', index);
+                        fs.fsWriteJSON('/lessons/index.json', index);
                     }
                 } catch (e) { /* VFS not available */ }
                 var msg = '💡 Self-improvement: ' + anomalies.length + ' anomaly(ies)';
diff --git a/modules/core/module-loader.js b/modules/core/module-loader.js
index 3204af0..836672d 100644
--- a/modules/core/module-loader.js
+++ b/modules/core/module-loader.js
@@ -4,7 +4,7 @@
     // Core module bundle loaded synchronously in main.html.
     // This loader only handles version cache-busting, splash, terminal init, and optional ext modules.
 
-    const LATEST_VER = 'v4.6.107';
+    const LATEST_VER = 'v4.6.108';
     const CACHE = '?v=' + LATEST_VER;
     const stored = localStorage.getItem('webx11_cache_ver');
     if (stored !== LATEST_VER) {
diff --git a/modules/core/module-system.js b/modules/core/module-system.js
index 40b0861..43bb0b1 100644
--- a/modules/core/module-system.js
+++ b/modules/core/module-system.js
@@ -743,7 +743,11 @@
                         if (helpEntry) {
                             this.terminal.print(helpEntry, 'info');
                         } else {
-                            this.terminal.print(`No help available for ${cmd}`, 'warning');
+                            // MAINT-019: a registered command with no help line answered "No help
+                            // available", which reads as if the command does not exist. Name the
+                            // module that owns it so the user knows where to look.
+                            const owner = allCommands[cmd];
+                            this.terminal.print(`${cmd} — registered by ${owner}, which publishes no help line for it. Try: help`, 'warning');
                         }
                     } else {
                         this.terminal.print(`No help available for ${cmd}`, 'warning');
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);
+}