fix(newos4): six crash classes from the feedback queue (v4.6.158)

Each item is symptom -> cause -> fix, re-verified against the served bytes.

1. debug-ai panel threw "Cannot read properties of undefined (reading 'substring')"
   (RPT-20261108-231622). _updateDebugPanel and two sibling previews called
   JSON.stringify(entry.args).substring(); JSON.stringify(undefined) returns
   undefined, and _toolCallLog entries carry args: undefined for any tool call
   with no arguments. All three previews now go through _formatToolArgs(), which
   renders "null" and never throws.

2. test_module threw "Cannot convert undefined or null to object"
   (RPT-20261108-232127). Object.keys(instance.commands) assumed every module
   initialises a command map. The throw landed after loadModuleFromCode had
   already succeeded, so the rolledBack:true branches were skipped and an
   unverified module stayed loaded. Both sites now require instance.commands.

3. list_files threw "originalPath.replace is not a function" (RPT-20261109-172742,
   3 occurrences in errors.json). A model can send a non-string path despite the
   schema. The path family (list_files/read_file/write_file/make_directory/
   delete_file) now coerces through _pathArg() and answers the tool's own honest
   error instead of a TypeError.

4. wpm search failed for EVERY keyword (RPT-20261109-123907): packages.json entry
   `kanban` used `description` while the other 31 use `desc`, and search() called
   pkg.desc.toLowerCase() mid-loop. Catalog reads now go through _pkg() /
   _packageMap() (desc || description, values coerced to strings), and the kanban
   entry carries name/version/desc/commands. Re-running the original loop for
   pdf/git/zzz is clean.

5. wx/webxai/webx turned a chat-lock timeout into an unhandled rejection
   (RPT-20261107-150726): forwardToAI() called chat(args) in a synchronous
   function without returning or catching the promise, so the 10 s busy throw
   never reached dispatchCommand's catch. It now returns the promise with a
   .catch that prints "AI error: ..." through terminal.print — console.error is
   hooked by the debug supervisor and would re-file the same report.

6. CryptoGzip._base64ToBytes threw a raw DOMException on non-base64 input
   (RPT-20261102-203616). It now validates first and throws
   Error("not valid base64 input (<reason>)"). The duplicate shadowing
   definitions at the bottom of the class were deleted — the later copy is the
   one that carried the unguarded atob().

Also regenerated modules/core/core-bundle.js (generated, never hand-edited) and
bumped the build v4.6.157 -> v4.6.158 (main.html x3 + module-loader.js).

Verified: 35/35 node tests, including 6 new regression tests each proven red
against the pre-fix source; an independent orchestrator harness 36/36; and
newos4-maintain.py --fix all PASS after regenerating the stale changelog page.
Served bytes are byte-identical for the bundle, main.html and both ext modules,
and a live headless-Chromium run against v4.6.158 shows WpmModule.search('pdf')
returning 1 result, the debug panel rendering a no-arg entry as "null",
_base64ToBytes('grüße') raising a plain Error that names base64, and 0 JS errors
on load.

m.pull (RPT-20261102-211438) is closed as a usage error: no module in the tree
defines pull(); the real interfaces are the webdav-pull and model-pull commands.

1 files changed, 28 insertions, 14 deletions

diff --git a/modules/ext/cryptogzip.js b/modules/ext/cryptogzip.js
index cc275df..25b6ca4 100644
--- a/modules/ext/cryptogzip.js
+++ b/modules/ext/cryptogzip.js
@@ -190,8 +190,31 @@ class CryptoGzipModule {
         for (let i = 0; i < bytes.length; i++) s += String.fromCharCode(bytes[i]);
         return btoa(s);
     }
+    // Validate before atob(): atob() throws a raw DOMException (InvalidCharacterError / "characters
+    // outside of the Latin1 range") for arbitrary input, which escaped as an unhandledrejection when
+    // called from the node/JS console (RPT-20261102-203616-e2641bff). Everything atob() would reject
+    // is rejected here first, as a plain Error the command wrappers can print.
+    _base64InvalidReason(s) {
+        if (typeof s !== 'string') return 'expected a string, got ' + (s === null ? 'null' : typeof s);
+        const t = s.replace(/[\t\n\f\r ]/g, '');   // atob() ignores exactly these ASCII whitespace chars
+        if (t.length === 0) return null;           // atob('') === '' — keep the empty case working
+        if (!/^[A-Za-z0-9+/]*={0,2}$/.test(t)) {
+            const bad = t.match(/[^A-Za-z0-9+/=]/);
+            if (bad) return 'illegal character ' + JSON.stringify(bad[0]) + ' — expected A-Z a-z 0-9 + / =';
+            return 'misplaced or excessive "=" padding';
+        }
+        const rem = t.length % 4;
+        if (rem === 1) return 'length ' + t.length + ' is not a valid base64 length';
+        // Padding may be omitted (atob accepts that too), but when present the length must be a
+        // multiple of 4 — otherwise atob() throws "not correctly encoded".
+        if (t.indexOf('=') !== -1 && rem !== 0) return 'length ' + t.length + ' has incomplete "=" padding';
+        return null;
+    }
+    _isBase64(s) { return this._base64InvalidReason(s) === null; }
     _base64ToBytes(b64) {
-        const s = atob(b64);
+        const reason = this._base64InvalidReason(b64);
+        if (reason) throw new Error('not valid base64 input (' + reason + ')');
+        const s = atob(b64.replace(/[\t\n\f\r ]/g, ''));
         const u8 = new Uint8Array(s.length);
         for (let i = 0; i < s.length; i++) u8[i] = s.charCodeAt(i);
         return u8;
@@ -582,19 +605,10 @@ class CryptoGzipModule {
     }
 
     // ============================================================
-    // Base64 Helpers
-    // ============================================================
-
-    _bytesToBase64(bytes) {
-        const bin = Array.from(bytes, (b) => String.fromCharCode(b)).join('');
-        return btoa(bin);
-    }
-
-    _base64ToBytes(b64) {
-        const bin = atob(b64);
-        return Uint8Array.from(bin, (c) => c.charCodeAt(0));
-    }
-
+    // Base64 Helpers — defined once, above, next to the gzip code.
+    // (A second, later copy of _bytesToBase64/_base64ToBytes used to
+    // live here and silently shadow the first; it carried the unguarded
+    // atob() call. Do not re-add a duplicate.)
     // ============================================================
 
     registerCommands() {