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).

plugins/agenthub-sessions/skills/cwd-rollup/SKILL.md

@@ -0,0 +1,62 @@
+---
+description: >
+  Roll up Claude Code sessions by working directory (project) from Agent Monitor
+  data — session count, total cost, total tokens, and last-active timestamp per cwd
+  — so per-project activity can be compared at a glance. Use when summarizing where
+  effort and spend went across projects.
+---
+
+# CWD Rollup
+
+Aggregate session activity per working directory (project).
+
+## Input
+
+The user provides: **$ARGUMENTS**
+
+- Empty → roll up **all** working directories.
+- A path / project substring → restrict the rollup to matching cwds.
+- `top N` → keep only the N highest-cost (or highest-count) projects.
+
+## Data Sources
+
+| Endpoint | Returns |
+|----------|---------|
+| `GET /api/run/cwds` | the distinct working directories that have sessions — the rollup key set |
+| `GET /api/sessions?limit=N` | session list: id, status, model, cwd, started_at, ended_at, cost, metadata (usage_extras with token counts) |
+| `GET /api/pricing/cost` | fleet cost: total_cost, breakdown[{ model, input_tokens, output_tokens, cache_read_tokens, cache_write_tokens, cost, matched_rule }] — for the fleet total to compute each cwd's share |
+
+## Report Sections
+
+### 1. Key set
+`GET /api/run/cwds` for the canonical list of working directories. Apply the
+`$ARGUMENTS` filter (substring match) if one was given.
+
+### 2. Pull sessions
+`GET /api/sessions?limit=1000`. Bucket sessions by `cwd`.
+
+### 3. Aggregate per cwd
+For each working directory compute:
+- **sessions** — count.
+- **cost** — sum of the inline `cost` field across the bucket.
+- **tokens** — sum of input / output / cache-read / cache-write from each session's
+  metadata `usage_extras` (sum the four into a total, and keep input + output as the
+  "billable text" subtotal).
+- **last active** — the max `started_at` (or `ended_at`) in the bucket.
+- **models** — the distinct models seen.
+
+### 4. Share of fleet
+`GET /api/pricing/cost` for `total_cost`; show each cwd's cost as a percentage of the
+fleet total.
+
+### 5. Ranking
+Sort by cost descending by default (or count if the user asked); apply `top N`.
+
+## Output
+
+Markdown table: `project (cwd basename) | sessions | total tokens | cost | % of fleet | last active | models`.
+Currency as USD to 4 decimal places; token counts with thousands separators; sort
+cost-descending. Add a final TOTAL row summing the columns. Only count tokens that
+the session metadata actually carries — if `usage_extras` is absent for a session,
+note it as excluded rather than guessing. If the dashboard is unreachable, tell the
+user to start it with `npm start` from the repo root.