feat(web): add profile switcher — ProfilePickerDialog, sidebar cards, and PTY reconnect

[RobinAngele]

Frontend companion to #33056 (backend — merge first).

Adds the full profile switcher UI: a modal ProfilePickerDialog, two profile cards in the chat sidebar (read-only active + clickable picker), config-gated feature flags, and channel-bump wiring so the PTY reconnects under the new profile without a page reload.

What's added

web/src/components/ProfilePickerDialog.tsx (+196 lines, new file)

Modal dialog portaled to document.body. Lists all profiles (sorted: default first, then alphabetical), highlights the active one with a checkmark, shows loading/error/empty states. Calls api.activateProfile(name) on selection, then signals the parent to reconnect the PTY. Keyboard-accessible (Esc to close, backdrop click).

web/src/lib/api.ts (+8 lines)

• api.activateProfile(name) — POSTs to /api/profiles/{name}/activate via fetchJSON (auto session-token injection). Complements the existing api.getProfiles().

web/src/components/ChatSidebar.tsx (+60 / -2 lines)

• active profile card — read-only, always visible, shows the current profile name with a Crown icon. Fetched from the public /api/active-profile endpoint on mount.
• agent profile card — clickable, gated by chatByAgentProfile prop, opens the ProfilePickerDialog modal.
• handleProfileActivated calls onProfileActivated prop (parent bumps channel key → PTY reconnects in-place). No page reload.

web/src/App.tsx (+21 lines)

• Reads dashboard.chat_by_agent_profile from /api/config — defaults to true when absent.
• channelBumpKey state + bumpChannel() callback — bumped on profile switch so the PTY reconnects under the new HERMES_HOME.

web/src/pages/ChatPage.tsx (+17 / -5 lines)

• Accepts chatByAgentProfile, channelBumpKey, onProfileActivated props.
• Wires channelBumpKey into the channel useMemo dependency array — when bumped, a new channel ID is generated, the old PTY WebSocket closes, and a new one opens.
• Forwards chatByAgentProfile and onProfileActivated to both ChatSidebar instances.

Data flow

ProfilePickerDialog
→ api.activateProfile(name) // POST to backend, writes sticky file
→ onProfileActivated(name)
→ ChatSidebar.handleProfileActivated()
→ onProfileActivated() (prop)
→ App.bumpChannel() // channelBumpKey++
→ ChatPage channel memo re-computes
→ PTY WebSocket reconnects
→ _resolve_chat_argv() reads ~/.hermes/active_profile
→ HERMES_HOME = ~/.hermes/profiles/

Testing (after #33056 is deployed)

curl localhost:9119/api/active-profile # → {"name":"default"}
curl -X POST localhost:9119/api/profiles/acronyc/activate
cat ~/.hermes/active_profile # → acronyc

Open dashboard → sidebar shows active profile + clickable picker → PTY reconnects without page reload.

Dependencies

PR / Issue	What	Merge order
#33056	Backend: sticky file + activate endpoint + /api/active-profile	← merge first
#33739 (this PR)	Frontend: full profile switcher UI	2nd

Related

• feat(dashboard): add configurable Chat UI sub-features — chat system monitor, agent profile picker, and per-profile gating #30815 — original ProfilePickerDialog PR (3 bugs found in testing)
• hermes gateway run is profile-blind: serves boot-time active_profile, ignores live switches (v0.14.0) #30626 — Gateway is profile-blind (same root cause)
• Web Dashboard: multi-profile switching support (analysis, root causes, and recommended design) #10674 — Dashboard multi-profile switching analysis (original spec)