refactor!: rebrand CCAM to AgentHub

Clean break, no compatibility alias. Renames the product name, the CLI
binary (`ccam` -> `agenthub`), the env var prefix (`CCAM_` ->
`AGENTHUB_`), the Prometheus metric namespace (`ccam_*` ->
`agenthub_*`), the tmux session prefix (`ccam-lane-<id>` ->
`agenthub-lane-<id>`), the per-repo runtime profile directory
(`.ccam/profile` -> `.agenthub/profile`), the lanes state root
(`~/.claude/ccam-lanes` -> `~/.claude/agenthub-lanes`), the bundled
plugins (`plugins/ccam*` -> `plugins/agenthub*`) and their slash
commands (`/ccam-doctor` -> `/agenthub-doctor`, `/ccam:*` ->
`/agenthub:*`).

Because there is no alias, an existing install has to be updated by
hand: rename its `.ccam/profile` directory and any `CCAM_*` variables,
and reinstall the plugin under its new name.

Two other name families are deliberately left alone here, since they are
not just strings: the `Claude-Code-Monitor` repository/marketplace name,
and the `agent-dashboard` npm package plus its `~/.claude/agent-dashboard`
runtime directory, which holds the live database and needs a migration
rather than a rename.

Verified: server 1406/1406, client 459/459, `grep -i ccam` clean across
tracked files, `openapi.yaml` regenerated (95 paths, unchanged count).

docs/superpowers/specs/2026-07-29-workspace-ui-design.md

@@ -27,7 +27,7 @@ Two facts also make lanes look emptier than they are:
 
 ## Goal
 
-The reference screen's legibility, on CCAM's real data: a lane's state readable
+The reference screen's legibility, on AgentHub's real data: a lane's state readable
 from across the room, the pipeline large enough to trace, and the console present
 but out of the way until wanted.
 
@@ -37,7 +37,7 @@ but out of the way until wanted.
 - **The console collapses.** It keeps every capability from A; it starts
   collapsed and opens for the selected lane. Watching lanes is the default
   posture, driving one is the exception.
-- **Only real data.** No placeholder tiles for facts CCAM does not have
+- **Only real data.** No placeholder tiles for facts AgentHub does not have
   (tickets, preview ports, per-lane credentials). Branch/commit/CI are added
   because they can be read for real — see below.
 - **Detection expires.** A detection older than a TTL stops holding the floor.
@@ -59,7 +59,7 @@ A wired it. The console is unchanged behind its new disclosure — no prop of
 
 ## The card
 
-Reference layout, CCAM's fields, nothing invented:
+Reference layout, AgentHub's fields, nothing invented:
 
 | Row | Content | Source |
 |---|---|---|