fix(remote): stop the wake handlers shadowing each other; enforce the input cap

Two findings from a final review pass over the wake-on-LAN feature.

`_onRemoteHostWaking` / `_onRemoteHostWakeFailed` were defined in BOTH
`panels-ui.js` (toasts) and `host-wake-ui.js` (banner). Both files mix into
`CodemanApp.prototype` and `host-wake-ui.js` loads later, so the panels-ui copies
were silently shadowed: the toast never fired, and a wake started for a BACKGROUND
session (input on a non-active tab) produced no notification at all, since the
banner handler only acts on the active session. The handlers now live only in
`host-wake-ui.js`, show the toast unconditionally, and update the banner when the
woken session is the active one.

`appendBoundedPending` dropped only WHOLE chunks, so a single input value over the
cap (one large paste is one `input` value, up to the 100 KB input schema) was kept
in full: "bounded at 4 KB" held per chunk, not per session, and nothing was logged.
The surviving chunk's head is now trimmed too, code-point aware so a multi-byte
character is never split into a replacement char.

Adds the guard that would have caught the first one: every SSE dispatch handler must
be defined in exactly ONE frontend module. The existing test only asserts a handler
EXISTS somewhere, which two modules both satisfy while one is shadowed.

src/web/public/panels-ui.js

@@ -120,17 +120,13 @@ Object.assign(CodemanApp.prototype, {
 
 
   // Wake-on-LAN from user input on a sleeping remote host (see remote-wake.ts).
-  _onRemoteHostWaking(data) {
-    const label = data && data.label ? data.label : 'Remote host';
-    // Long enough to cover the wake + attach (~10s measured on a warm S3), and it
-    // is replaced by `remote:sessionReconnected` the moment the pane is back.
-    this.showToast(`Waking ${label} … input is queued`, 'info', { duration: 12000 });
-  },
-
-  _onRemoteHostWakeFailed(data) {
-    const label = data && data.label ? data.label : 'Remote host';
-    this.showToast(`${label} did not wake up — queued input is still held`, 'error', { duration: 15000 });
-  },
+  // ⚠️ The `remote:hostWaking` / `remote:hostWakeFailed` HANDLERS live in
+  // `host-wake-ui.js`, which owns the banner state. They are NOT redefined here:
+  // both files mix into `CodemanApp.prototype` and `host-wake-ui.js` is loaded
+  // later, so a second definition would silently shadow the banner update (and the
+  // toast would never fire — the exact silent no-op `sse-dispatch-table.test.ts`
+  // exists to prevent, which cannot see shadowing). The toasts are shown from the
+  // host-wake-ui handlers instead.
 
 
   // Bash tools