fix(newos4): name the real Ollama failure, bound auto-connect, fix the review findings

Second pass over v4.6.105, driven by an independent review that reproduced each item.

- ollama-manager.js: chat() now reports the captured cause ("Ollama error: Failed to fetch",
  "…: HTTP 500") instead of the generic "No provider responded"; _lastChatError is reset per
  call so an old reason is never replayed. chatWithTools carries the reason in its error string.
- ollama-manager.js: _ensureConnected() bounds connect() with a deadline (connectTimeoutMs,
  default 10 s). connect() uses a bare fetch(), so a blackholed endpoint previously left the
  shared in-flight promise pending forever and hung every later message — the old code failed
  fast. The attempt is now try/finally, so a throwing terminal.log() can no longer poison
  _connecting and suppress the retry on the next message.
- ollama-manager.js: an automatic connect no longer silently rewrites the user's saved model;
  the previous choice is restored in memory and in localStorage, and the user is told.
- ollama-manager.js: the DeepSeek empty-content branch returned top-level tool_calls with
  content '', so the caller pushed an assistant message with no tool_calls and then a
  role:'tool' reply — an orphan tool message, which is the HTTP 400 that branch exists to
  prevent. tool_calls now live inside the message as well.
- module-aiassist.js: a no-argument list_files returned the ROOT instead of the cwd (readDir('/')
  instead of ls()); it now means the current directory again. Error text keeps the path as the
  caller wrote it, and write_file distinguishes a read-only virtual path (/sys/…) from a missing
  parent instead of blaming the parent.

Tests: test-ollama-error-text.js (new, 14 asserts, RED 9/5 before the edit), test-ai-fs-tools.js
7 → 16 asserts (write onto a directory, /sys write, list a file, '/', no-arg cwd, relative path),
test-ollama-autoconnect.js 11 → 19 (blackholed endpoint settles + retries, saved model survives;
the old "connecting hint" assertion is now falsifiable — the reviewer showed it also matched
connect()'s pre-existing line). Suite: 10/10 files green. Live on v4.6.106: healthy auto-connect
42 ms with the hint; blackholed endpoint settles in 1242 ms with connectTimeoutMs=1200, prints
"timed out" and "unreachable", _connecting cleared.

3 files changed, 199 insertions, 1 deletions

diff --git a/modules/test/test-ai-fs-tools.js b/modules/test/test-ai-fs-tools.js
index c427783..3968abe 100644
--- a/modules/test/test-ai-fs-tools.js
+++ b/modules/test/test-ai-fs-tools.js
@@ -65,6 +65,58 @@ const run = async (ai, name, args) => JSON.parse(await ai.runTool(name, args));
         ok('D2 content landed', vfs.readFile('/missing/dir/f.txt') === 'x');
     }
 
+    // E. write onto a directory node is refused, and the directory survives
+    {
+        const { ai, vfs } = mk();
+        vfs.mkdirRecursive('/adir');
+        vfs.writeFile('/adir/keep.txt', 'k');
+        const res = await ai.runTool('write_file', { path: '/adir', content: 'x' });
+        ok('E1 write onto a directory is refused', /Write FAILED/.test(String(res)), String(res));
+        ok('E2 directory contents intact', vfs.readFile('/adir/keep.txt') === 'k');
+    }
+
+    // F. a read-only virtual path names that as the reason
+    {
+        const { ai } = mk();
+        const res = await ai.runTool('write_file', { path: '/sys/info', content: 'x' });
+        ok('F1 virtual path reports read-only', /Write FAILED: \/sys\/info — read-only virtual path/.test(String(res)), String(res));
+    }
+
+    // G. list_files on a FILE is an error, on '/' is the root listing
+    {
+        const { ai, vfs } = mk();
+        vfs.writeFile('/file.txt', 'x');
+        const onFile = await run(ai, 'list_files', { path: '/file.txt' });
+        ok('G1 listing a file reports Directory not found', !!onFile.error && /\/file\.txt/.test(onFile.error), JSON.stringify(onFile));
+        const onRoot = await run(ai, 'list_files', { path: '/' });
+        ok('G2 root lists the virtual sys mount', Array.isArray(onRoot) && onRoot.some(e => e.name === 'sys'), JSON.stringify(onRoot).slice(0, 120));
+    }
+
+    // H. no argument means the CURRENT directory, not the root
+    {
+        const { ai, vfs } = mk();
+        vfs.mkdirRecursive('/work');
+        vfs.writeFile('/work/inside.txt', 'x');
+        vfs.writeFile('/root-only.txt', 'y');
+        vfs.currentPath = ['work'];
+        const cwd = await run(ai, 'list_files', {});
+        const names = (cwd.error ? [] : cwd.map(e => e.name));
+        ok('H1 no-arg lists the cwd', names.includes('inside.txt') && !names.includes('root-only.txt'), JSON.stringify(cwd).slice(0, 140));
+        ok('H2 cwd is restored after the call', JSON.stringify(vfs.currentPath) === '["work"]', JSON.stringify(vfs.currentPath));
+    }
+
+    // I. a relative path resolves from the cwd
+    {
+        const { ai, vfs } = mk();
+        vfs.mkdirRecursive('/docs');
+        vfs.writeFile('/docs/sub.txt', 'x');
+        vfs.currentPath = ['docs'];
+        const res = await run(ai, 'list_files', { path: 'sub.txt' });
+        ok('I1 a relative file path is resolved, not guessed', !!res.error, JSON.stringify(res));
+        const dirRes = await run(ai, 'list_files', { path: '.' });
+        ok('I2 "." lists the cwd', Array.isArray(dirRes) && dirRes.some(e => e.name === 'sub.txt'), JSON.stringify(dirRes).slice(0, 120));
+    }
+
     if (fails === 0) {
         console.log('test-ai-fs-tools: ' + passes + ' passed, 0 failed');
     } else {
diff --git a/modules/test/test-ollama-autoconnect.js b/modules/test/test-ollama-autoconnect.js
index b9db4ff..12b0786 100644
--- a/modules/test/test-ollama-autoconnect.js
+++ b/modules/test/test-ollama-autoconnect.js
@@ -59,7 +59,7 @@ const json = (body, okFlag = true) => Promise.resolve({ ok: okFlag, status: okFl
         const res = await om.chat('ping');
         const text = out.map(o => o.text).join(' | ');
         ok('A1 connect is attempted lazily', seen.some(u => u.includes('/api/tags')), seen.join(', '));
-        ok('A2 the user sees a connecting hint', /Connecting to Ollama/.test(text), text.slice(0, 160));
+        ok('A2 the user sees a first-use hint', /connecting on first use/.test(text), text.slice(0, 160));
         ok('A3 manager is connected after the attempt', om.connected === true);
         ok('A4 the message is answered', String(res).includes('pong'), String(res).slice(0, 120));
         ok('A5 no "ollamaconnect first" error', !/ollamaconnect first/.test(text), text.slice(0, 200));
@@ -89,6 +89,38 @@ const json = (body, okFlag = true) => Promise.resolve({ ok: okFlag, status: okFl
         ok('C1 three concurrent messages probe /api/tags once', tagCalls === 1, 'tagCalls=' + tagCalls);
     }
 
+    // D. a blackholed endpoint must not hang every later message
+    {
+        const { om, out } = mk(() => new Promise(() => {}));   // never settles
+        om.connectTimeoutMs = 100;
+        const t0 = Date.now();
+        const res = await om.chat('ping');
+        const ms = Date.now() - t0;
+        const text = out.map(o => o.text).join(' | ');
+        ok('D1 chat settles on a silent endpoint', ms < 3000, ms + 'ms');
+        ok('D2 returns null', res === null, String(res));
+        ok('D3 the timeout is reported', /timed out/.test(text), text.slice(0, 220));
+        ok('D4 _connecting is cleared', om._connecting === null, String(om._connecting));
+        const before = out.length;
+        await om.chat('again');
+        ok('D5 the next message retries the connect', out.length > before, 'lines ' + before + ' -> ' + out.length);
+    }
+
+    // E. an automatic connect must not rewrite the model the user saved
+    {
+        store['webx11_ollama_model'] = 'my-saved-model';
+        const { om, out } = mk((url) => url.includes('/api/tags')
+            ? json({ models: [{ name: 'other-model' }] })
+            : json({ response: 'x', eval_count: 1, prompt_eval_count: 1 }));
+        om.currentModel = 'my-saved-model';
+        await om._ensureConnected();
+        const text = out.map(o => o.text).join(' | ');
+        ok('E1 the saved model survives an auto-connect', om.currentModel === 'my-saved-model', om.currentModel);
+        ok('E2 the stored preference is restored', store['webx11_ollama_model'] === 'my-saved-model', String(store['webx11_ollama_model']));
+        ok('E3 the user is told why', /Keeping your saved model/.test(text), text.slice(0, 200));
+        delete store['webx11_ollama_model'];
+    }
+
     if (fails === 0) {
         console.log('test-ollama-autoconnect: ' + passes + ' passed, 0 failed');
     } else {
diff --git a/modules/test/test-ollama-error-text.js b/modules/test/test-ollama-error-text.js
new file mode 100644
index 0000000..01a17b4
--- /dev/null
+++ b/modules/test/test-ollama-error-text.js
@@ -0,0 +1,114 @@
+// modules/test/test-ollama-error-text.js — run: node
+// Proves a failed Ollama chat names the REAL cause ("Failed to fetch", "HTTP 500")
+// instead of the generic "No provider responded", and that a stale reason captured by
+// an earlier, unrelated failure is never replayed on a later call.
+const fsMod = require('fs'), path = require('path');
+const CORE = path.join(__dirname, '..', 'core');
+
+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.window = { addEventListener: () => {}, location: { origin: 'https://webx11.duckdns.org' } };
+global.document = { addEventListener: () => {} };
+
+const OllamaManager = new Function(
+    fsMod.readFileSync(path.join(CORE, 'ollama-manager.js'), 'utf8') + '\nreturn OllamaManager;')();
+
+let passes = 0, fails = 0;
+function ok(name, cond, detail) {
+    if (cond) { passes++; return; }
+    fails++;
+    console.log('FAIL ' + name + (detail ? ' — ' + detail : ''));
+}
+
+// A manager that is already "connected" so chat() goes straight to the provider loop:
+// this test is about provider failure text, not about the lazy-connect gate.
+function mk() {
+    const out = [];
+    const term = {
+        print: (m, t) => out.push({ text: String(m), type: t || '' }),
+        log: () => {},
+        printStreamingResponse: t => out.push({ text: String(t), type: 'stream' }),
+    };
+    const om = Object.create(OllamaManager.prototype);
+    Object.assign(om, {
+        terminal: term,
+        connected: true, models: [], currentModel: 'm1',
+        endpoint: 'https://webx11.duckdns.org/ollama', fallbackEndpoints: [],
+        providers: [{ name: 'Ollama', type: 'ollama', endpoint: 'https://webx11.duckdns.org/ollama', model: 'm1', priority: 1, enabled: true }],
+        currentProvider: null, fallbackCount: 0, responseHooks: [], _usageLog: [], _usageBuffer: [],
+        _abortController: null, _connecting: null, streamEnabled: false,
+        saveSettings: () => {}, _saveProviders: () => {}, _logUsage: () => {}, _flushUsageLog: () => {},
+    });
+    om.currentProvider = om.providers[0];
+    return { om, out };
+}
+
+const json = (body, okFlag = true) => Promise.resolve({
+    ok: okFlag, status: okFlag ? 200 : 500, json: async () => body,
+});
+const textOf = out => out.map(o => o.text).join(' | ');
+const errorLines = out => out.filter(o => /Ollama error/.test(o.text)).map(o => o.text).join(' | ');
+
+(async () => {
+    // A. every provider endpoint rejects: the user must see the transport cause
+    {
+        const { om, out } = mk();
+        global.fetch = () => Promise.reject(new TypeError('Failed to fetch'));
+        const res = await om.chat('ping');
+        const text = textOf(out), line = errorLines(out);
+        ok('A1 chat() returns null', res === null, String(res));
+        ok('A2 error line mentions "Ollama error"', /Ollama error/.test(line), 'line=' + JSON.stringify(line));
+        ok('A3 error line names the real cause "Failed to fetch"', /Failed to fetch/.test(line), 'line=' + JSON.stringify(line));
+        ok('A4 generic "No provider responded" is not printed', !/No provider responded/.test(text), text.slice(0, 240));
+    }
+
+    // B. provider answers HTTP 500: the status code must survive into the message
+    {
+        const { om, out } = mk();
+        global.fetch = () => json({ error: 'kaboom' }, false);
+        const res = await om.chat('ping');
+        const line = errorLines(out);
+        ok('B1 chat() returns null', res === null, String(res));
+        ok('B2 error line carries "Ollama error"', /Ollama error/.test(line), 'line=' + JSON.stringify(line));
+        ok('B3 error line carries the HTTP status "500"', /500/.test(line), 'line=' + JSON.stringify(line));
+        ok('B4 generic "No provider responded" is not printed', !/No provider responded/.test(textOf(out)), textOf(out).slice(0, 240));
+    }
+
+    // C. the reason is per-call state: a later call must not replay it
+    {
+        const { om, out } = mk();
+
+        // C1: a genuine failure captures a reason
+        global.fetch = () => Promise.reject(new TypeError('Failed to fetch'));
+        const first = await om.chat('first');
+
+        // C2: a success in between
+        global.fetch = () => json({ response: 'pong', eval_count: 1, prompt_eval_count: 1 });
+        const second = await om.chat('second');
+        const failMentionsAfterSuccess = out.filter(o => /Failed to fetch/.test(o.text)).length;
+
+        // C3: a provider that fails WITHOUT throwing (empty body) — no reason to report,
+        // so the fallback wording must come back instead of the stale transport error.
+        global.fetch = () => json({ response: '', eval_count: 1, prompt_eval_count: 1 });
+        const third = await om.chat('third');
+        const lastLine = out.filter(o => /Ollama error/.test(o.text)).map(o => o.text).pop() || '';
+
+        ok('C1 first call returns null', first === null, String(first));
+        ok('C2 successful call still answers', String(second).includes('pong'), String(second).slice(0, 120));
+        ok('C3 the captured reason is logged exactly once', failMentionsAfterSuccess === 1, 'count=' + failMentionsAfterSuccess);
+        ok('C4 third call returns null', third === null, String(third));
+        ok('C5 no-reason failure falls back to the generic wording', /No provider responded/.test(lastLine), 'last=' + JSON.stringify(lastLine));
+        ok('C6 the stale "Failed to fetch" reason is not replayed', !/Failed to fetch/.test(lastLine), 'last=' + JSON.stringify(lastLine));
+    }
+
+    if (fails === 0) {
+        console.log('test-ollama-error-text: ' + passes + ' passed, 0 failed');
+    } else {
+        console.log('test-ollama-error-text: ' + passes + ' passed, ' + fails + ' FAILED');
+        process.exit(1);
+    }
+})();