protocol, clients: acks, queue notices and reconnect without duplicates ...

- client_id is echoed in message_accepted / message_queued; queue overflow
  broadcasts message_dropped to every socket watching the session
- stream_end / stream_stopped carry message_index, the global display rank
  that also stamps history rows
- webclient: cheap session_sync via /sessions/{id}/meta, the ack deadline is
  armed at the write and re-armed while a run is active, fatal 4003/4004 stop
  the reconnect loop instead of retrying forever
- TUI: WsBridge posts WsResumed / MessageWritten / SessionUnavailable, the app
  drops the half-written turn on reconnect, shows queued and not-delivered
  markers on the bubble, and reloads history only when the meta token changes
- dist rebuilt

webclient: make session loads cheap, cancellable and honest ...

Opening a session moved ~1 MB of history JSON and a 1.5 MB bundle
uncompressed, then reloaded the whole transcript on every WebSocket
reconnect; a failed request wiped what was on screen.

Server: GZipMiddleware(1 KB) - one history page shrinks 5.1x, the SPA
bundle 3.2x.

Client:
- session_sync asks /meta instead of reloading history, and only when
  the view is idle;
- session loading keeps the previous transcript until the new data
  arrives, aborts the request it replaced, ignores stale responses and
  surfaces a retryable error banner;
- search-jump pagination no longer pages through the previous session's
  history;
- REST calls get a 30 s timeout and caller abort support;
- WS queue overflow rejects the message and marks the bubble "not sent"
  instead of silently dropping the oldest;
- tool card bodies mount on first open (a 38-card session drops ~1 MB of
  markup and ~25k elements);
- identical /sessions requests coalesce, the streaming watch is a cheap
  signature, the content-tool key is one store computed, useTime shares
  one 30 s ticker, connect() clears the retry timer.

e2e opens result cards explicitly now that bodies are lazy.

tools: split filesystem into read, write and file_ai ...

- filesystem_read: read, list, find, find_up, grep, info, exists, diff
- filesystem_write: write, append, edit, edit_lines, insert, mkdir, move, copy, delete
- file_ai: ask (was query), edit (was smart_edit)
- paged numbered reads (500 lines / 50 KB), raw copy mode, binary refusal
- nearest-match and numbered-copy hints on failed edits, context after edit
- guards: empty overwrite, non-empty delete, move/copy overwrite
- cross-tool redirects instead of silent wrong-action errors
- legacy 'filesystem' stays for archived sessions (compression, renderers, webclient)
- profiles, prompts, docs and manuals updated; TUI and webclient render the new tools

webclient: split the chat store into area modules