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.

1 files changed, 8 insertions, 4 deletions

diff --git a/modules/core/module-aiassist.js b/modules/core/module-aiassist.js
index 303f9c2..ac8d297 100644
--- a/modules/core/module-aiassist.js
+++ b/modules/core/module-aiassist.js
@@ -2379,10 +2379,11 @@ buildSystemPrompt() {
                             // MAINT-011: readDir() resolves the virtual mounts and returns null for a
                             // path that does not exist. The old hand-rolled walk over root.content could
                             // not see /sys, so a directory the UI shows answered "Directory not found".
-                            const entries = fsapi.readDir(p || '/');
+                            // No argument means "the current directory", which ls() already does.
+                            const entries = p ? fsapi.readDir(p) : fsapi.ls();
                             fsapi.currentPath = saved;
                             if (entries === null || entries === undefined) {
-                                return JSON.stringify({ error: `Directory not found: ${p || '/'}` });
+                                return JSON.stringify({ error: `Directory not found: ${originalPath || p}` });
                             }
                             return JSON.stringify(entries.map(f => ({ name: f.name, type: f.type, size: f.size })));
                         }
@@ -2430,9 +2431,12 @@ buildSystemPrompt() {
                             const wrote = this.terminal.fs.writeFile(path, content);
                             this.terminal.fs.currentPath = savedW;
                             if (!wrote) {
-                                return `Write FAILED: ${path} — parent directory missing or target is a directory; nothing was written`;
+                                const why = (typeof this.terminal.fs._isVirtualPath === 'function' && this.terminal.fs._isVirtualPath(wp))
+                                    ? 'read-only virtual path'
+                                    : 'parent directory missing or target is a directory';
+                                return `Write FAILED: ${wp} — ${why}; nothing was written`;
                             }
-                            return `File written: ${path} (${content.length} chars)`;
+                            return `File written: ${wp} (${content.length} chars)`;
                         }
                         case 'make_directory': {
                             const mp = a.path || '';