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/data/pipelines/ship-feature.json

@@ -1,7 +1,7 @@
 {
   "id": "ship-feature",
   "name": "Ship feature (lane pipeline)",
-  "skill": "/ccam:ship-feature-lane",
+  "skill": "/agenthub:ship-feature-lane",
   "nodes": [
     {
       "id": "intake",
@@ -22,7 +22,7 @@
         },
         {
           "tool": "Bash",
-          "match": "\\bccam\\b[^;&|]*\\bfeature activate\\b"
+          "match": "\\bagenthub\\b[^;&|]*\\bfeature activate\\b"
         },
         {
           "tool": "Agent",
@@ -90,7 +90,7 @@
       "label": "CI gates + preflight",
       "icon": "🧪",
       "gate": true,
-      "command": "ccam lanes hook ci-gate",
+      "command": "agenthub lanes hook ci-gate",
       "aliases": [
         "pre-push-gate",
         "tests",
@@ -100,7 +100,7 @@
       "detect": [
         {
           "tool": "Bash",
-          "match": "\\bccam\\b[^;&|]*(\\bhook ci-gate\\b|\\bsync-base --check\\b)"
+          "match": "\\bagenthub\\b[^;&|]*(\\bhook ci-gate\\b|\\bsync-base --check\\b)"
         },
         {
           "tool": "Bash",
@@ -113,7 +113,7 @@
       "label": "E2e on feature branch",
       "icon": "🧪",
       "gate": false,
-      "command": "ccam lanes up --qc",
+      "command": "agenthub lanes up --qc",
       "aliases": [
         "e2e",
         "e2e-scoped",
@@ -123,7 +123,7 @@
       "detect": [
         {
           "tool": "Bash",
-          "match": "\\bccam\\b[^;&|]*(\\bup --qc\\b|\\bhook e2e\\b)"
+          "match": "\\bagenthub\\b[^;&|]*(\\bup --qc\\b|\\bhook e2e\\b)"
         }
       ]
     },
@@ -132,7 +132,7 @@
       "label": "E2e passed",
       "icon": "🧪",
       "gate": true,
-      "command": "ccam stage e2e-feature-passed",
+      "command": "agenthub stage e2e-feature-passed",
       "aliases": [
         "e2e-passed"
       ]
@@ -164,7 +164,7 @@
       "label": "QC plan",
       "icon": "📋",
       "gate": false,
-      "command": "ccam stage qc-plan",
+      "command": "agenthub stage qc-plan",
       "aliases": []
     },
     {
@@ -172,7 +172,7 @@
       "label": "Browser QC",
       "icon": "🔍",
       "gate": true,
-      "command": "ccam lanes proof-link",
+      "command": "agenthub lanes proof-link",
       "aliases": [],
       "detect": [
         {
@@ -181,7 +181,7 @@
         },
         {
           "tool": "Bash",
-          "match": "\\bccam\\b[^;&|]*\\blanes proof-link\\b"
+          "match": "\\bagenthub\\b[^;&|]*\\blanes proof-link\\b"
         }
       ]
     },
@@ -252,7 +252,7 @@
       "label": "Reported",
       "icon": "📣",
       "gate": false,
-      "command": "ccam stage reported",
+      "command": "agenthub stage reported",
       "aliases": []
     },
     {
@@ -260,7 +260,7 @@
       "label": "Watching PR",
       "icon": "👁",
       "gate": false,
-      "command": "ccam lanes ci status",
+      "command": "agenthub lanes ci status",
       "aliases": [
         "pr-comment-fix"
       ],
@@ -276,7 +276,7 @@
       "label": "Merged — post-verify",
       "icon": "🔗",
       "gate": false,
-      "command": "ccam stage merged",
+      "command": "agenthub stage merged",
       "aliases": []
     },
     {
@@ -284,7 +284,7 @@
       "label": "Done",
       "icon": "✅",
       "gate": false,
-      "command": "ccam stage done",
+      "command": "agenthub stage done",
       "aliases": [
         "complete",
         "completed"