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).

server/routes/metrics.js

@@ -74,26 +74,26 @@ function appendMetric(out, name, help, type, samples) {
 router.get("/", (_req, res) => {
   const out = [];
 
-  appendMetric(out, "ccam_up", "1 when the dashboard API is serving this scrape.", "gauge", [
+  appendMetric(out, "agenthub_up", "1 when the dashboard API is serving this scrape.", "gauge", [
     { value: 1 },
   ]);
   appendMetric(
     out,
-    "ccam_build_info",
+    "agenthub_build_info",
     "Dashboard build info; the value is always 1, the version rides on the label.",
     "gauge",
     [{ labels: { version: APP_VERSION }, value: 1 }]
   );
   appendMetric(
     out,
-    "ccam_process_uptime_seconds",
+    "agenthub_process_uptime_seconds",
     "Uptime of the dashboard server process in seconds.",
     "gauge",
     [{ value: Math.round(process.uptime()) }]
   );
   appendMetric(
     out,
-    "ccam_process_resident_memory_bytes",
+    "agenthub_process_resident_memory_bytes",
     "Resident set size (RSS) of the dashboard server process in bytes.",
     "gauge",
     [{ value: process.memoryUsage().rss }]
@@ -103,7 +103,7 @@ router.get("/", (_req, res) => {
   const sessionCounts = new Map(stmts.sessionStatusCounts.all().map((r) => [r.status, r.count]));
   appendMetric(
     out,
-    "ccam_sessions",
+    "agenthub_sessions",
     "Number of sessions by lifecycle status.",
     "gauge",
     SESSION_STATUSES.map((status) => ({
@@ -116,7 +116,7 @@ router.get("/", (_req, res) => {
   const agentCounts = new Map(stmts.agentStatusCounts.all().map((r) => [r.status, r.count]));
   appendMetric(
     out,
-    "ccam_agents",
+    "agenthub_agents",
     "Number of agents (main + subagents) by status.",
     "gauge",
     AGENT_STATUSES.map((status) => ({ labels: { status }, value: agentCounts.get(status) || 0 }))
@@ -125,7 +125,7 @@ router.get("/", (_req, res) => {
   // Event throughput (monotonic — a counter).
   appendMetric(
     out,
-    "ccam_events_total",
+    "agenthub_events_total",
     "Total hook and synthetic events recorded since the database was created.",
     "counter",
     [{ value: stmts.countEvents.get().count }]
@@ -140,7 +140,7 @@ router.get("/", (_req, res) => {
   }
   appendMetric(
     out,
-    "ccam_websocket_clients",
+    "agenthub_websocket_clients",
     "Currently connected realtime (WebSocket) dashboard clients.",
     "gauge",
     [{ value: clients }]
@@ -158,7 +158,7 @@ router.get("/", (_req, res) => {
   }
   appendMetric(
     out,
-    "ccam_remote_sources",
+    "agenthub_remote_sources",
     "Configured Remote Data Sources, split by auto-sync enabled state.",
     "gauge",
     [
@@ -181,7 +181,7 @@ router.get("/", (_req, res) => {
     .get();
   appendMetric(
     out,
-    "ccam_tokens_total",
+    "agenthub_tokens_total",
     "Cumulative token usage across all sessions, by kind.",
     "counter",
     [