web_fetch updates

kernel/bin/agent

@@ -1665,6 +1665,43 @@ async function bareAgentCompleteOnce(opts) {
 
 /** HTTP fetch + HTML extract helpers for agent `web_fetch` tool (preamble for /bin/agent). */
 
+/**
+ * @param {unknown} e
+ * @returns {string}
+ */
+function bareWebFmtErr(e) {
+  if (e == null) return '(null)'
+  if (typeof e === 'string') return e
+  if (typeof e !== 'object') return String(e)
+  const o = /** @type {Record<string, unknown>} */ (e)
+  const msg = o.message
+  if (typeof msg === 'string' && msg.trim()) return msg
+  if (typeof msg === 'number' || typeof msg === 'boolean') return String(msg)
+  const nm = o.name
+  const code = o.code
+  /** @type {string[]} */
+  const bits = []
+  if (typeof nm === 'string' && nm.trim()) bits.push(nm)
+  if (code !== undefined && code !== null && String(code) !== '')
+    bits.push('code=' + String(code))
+  if (bits.length) return bits.join(' ')
+  try {
+    const j = JSON.stringify(o)
+    if (j && j !== '{}' && j !== '[]') return j.slice(0, 400)
+  } catch {
+    /* ignore */
+  }
+  try {
+    if (typeof (/** @type {{ toString?: () => string }} */ (o)).toString === 'function') {
+      const t = /** @type {{ toString: () => string }} */ (o).toString()
+      if (t && t !== '[object Object]') return t.slice(0, 400)
+    }
+  } catch {
+    /* ignore */
+  }
+  return 'unknown_error'
+}
+
 /**
  * @param {Record<string, unknown>} ctx
  * @returns {typeof fetch | null}
@@ -2075,7 +2112,7 @@ async function bareWebRunTool(o) {
       res = await fetchFn(currentUrl, init)
     } catch (e) {
       clearTimeout(timer)
-      const msg = e && typeof e === 'object' && 'message' in e ? String(e.message) : String(e)
+      const msg = bareWebFmtErr(e)
       return {
         ok: false,
         error: 'web_fetch: request failed: ' + msg.slice(0, 400),
@@ -2147,7 +2184,7 @@ async function bareWebRunTool(o) {
     try {
       bodyRead = await bareWebReadBodyLimited(res, maxBytes, signal || undefined)
     } catch (e) {
-      const msg = e && typeof e === 'object' && 'message' in e ? String(e.message) : String(e)
+      const msg = bareWebFmtErr(e)
       return {
         ok: false,
         error: 'web_fetch: read body failed: ' + msg.slice(0, 400),
@@ -3438,8 +3475,7 @@ async function bareAgentDispatchTool(o) {
         })
         return bareAgentJsonResult(out)
       } catch (e) {
-        const msg =
-          e && typeof e === 'object' && 'message' in e ? String(e.message) : String(e)
+        const msg = bareWebFmtErr(e)
         return bareAgentJsonResult({ ok: false, error: msg })
       }
     }

kernel/etc/bare-os/posix_utilities.json

@@ -1,7 +1,7 @@
 {
   "schema": 2,
   "profileId": "bare-os-posix-like",
-  "generatedAt": "2026-04-22T04:14:01.274Z",
+  "generatedAt": "2026-04-22T05:30:18.374Z",
   "note": "Sparse POSIX Issue 7 coverage hints for /bin utilities. Omitted command names are not yet profiled here.",
   "commandIndex": [
     {

kernel/lib/bare/shell-completion.json

@@ -1,6 +1,6 @@
 {
   "schema": 1,
-  "atMs": 1776831241273,
+  "atMs": 1776835818373,
   "commands": [
     "agent",
     "arch",