feat: add fast mode toggle for OpenAI models

docs/web/control-ui.md

@@ -75,7 +75,7 @@ The Control UI can localize itself on first load based on your browser locale, a
 - Stream tool calls + live tool output cards in Chat (agent events)
 - Channels: WhatsApp/Telegram/Discord/Slack + plugin channels (Mattermost, etc.) status + QR login + per-channel config (`channels.status`, `web.login.*`, `config.patch`)
 - Instances: presence list + refresh (`system-presence`)
-- Sessions: list + per-session thinking/verbose overrides (`sessions.list`, `sessions.patch`)
+- Sessions: list + per-session thinking/fast/verbose/reasoning overrides (`sessions.list`, `sessions.patch`)
 - Cron jobs: list/add/edit/run/enable/disable + run history (`cron.*`)
 - Skills: status, enable/disable, install, API key updates (`skills.*`)
 - Nodes: list + caps (`node.list`)

docs/web/tui.md

@@ -37,7 +37,7 @@ Use `--password` if your Gateway uses password auth.
 - Header: connection URL, current agent, current session.
 - Chat log: user messages, assistant replies, system notices, tool cards.
 - Status line: connection/run state (connecting, running, streaming, idle, error).
-- Footer: connection state + agent + session + model + think/verbose/reasoning + token counts + deliver.
+- Footer: connection state + agent + session + model + think/fast/verbose/reasoning + token counts + deliver.
 - Input: text editor with autocomplete.
 
 ## Mental model: agents + sessions
@@ -92,6 +92,7 @@ Core:
 Session controls:
 
 - `/think <off|minimal|low|medium|high>`
+- `/fast <status|on|off>`
 - `/verbose <on|full|off>`
 - `/reasoning <on|off|stream>`
 - `/usage <off|tokens|full>`