Video calls (PairUX→ASCII), agent@ chat, and finger routes

ssh video-<code>@ joins a PairUX/LiveKit call rendered as truecolor
ASCII (▀ half-blocks, 2 pixels per cell); video@ prompts for a code.
Codes are minted by PairUX only. Pipeline: VP8 RTP → PLI keyframe
requests → ivfwriter remux → ffmpeg decode/scale → RGB24 → ANSI →
bubbletea over the SSH PTY. Subscriber-only, no audio in v1.

ssh agent@ opens a persisted chat with the operator's agent —
AGENTBBS_AGENT_CMD runs per message (stdin→stdout), e.g. `claude -p`.

ssh <member>@ with someone else's name prints a classic finger card
(.plan, member since, last seen) and disconnects; your own name still
enters the hub.

cmd/lkpublish: dev publisher for testing (explicit -fps pacing; lksdk
IVF replay mispaces from file timebase alone, measured 1fps from a
15fps file; dimensions required or dynacast pauses the track).

Verified end-to-end against livekit-server --dev: 128k truecolor cells
/ 20k distinct colors streamed over a real SSH session; chat round-trip
and finger card verified over SSH. Go toolchain pinned to 1.26 via
mise.toml (lksdk requirement).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/social.md

@@ -0,0 +1,41 @@
+# Social Routes Addendum: agent@ and finger
+
+## agent@ — talk to the operator
+
+```bash
+ssh agent@profullstack.com
+```
+
+A chat TUI: visitors talk to the operator's AI agent. Every message (both
+directions) is persisted to `chat_messages`, so the operator can read
+conversations later; live operator takeover arrives with the M2 admin
+console.
+
+The agent backend is one command, configured by env:
+
+| Var | Meaning |
+|---|---|
+| `AGENTBBS_AGENT_CMD` | command per message: user text on stdin, reply on stdout (120s timeout). e.g. `claude -p`, a logicsrc/commandboard agent, any script. Unset = "message saved for the operator" mode. |
+
+Identity: if the visitor's SSH key matches a member, the transcript is tied
+to their account; otherwise it's keyed by remote address as a guest.
+
+## finger — `ssh <member>@`
+
+SSH'ing to an account name that exists but **isn't yours** prints a classic
+finger card and disconnects:
+
+```
+$ ssh anthony@profullstack.com
+
+  Login: anthony    Kind: member
+  Member since: 2026-06-11    Last seen: 2026-06-11 11:07 UTC
+  Plan:
+    building agentbbs.
+```
+
+- The plan is read from the member's `~/.plan` (or `plan.txt`) in their data
+  directory.
+- Your own name (key matches) still lands you in the hub; unclaimed names
+  fall through to the hub's claim flow.
+- Works keyless — like real finger.