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-insights/skills/benchmark/SKILL.md

@@ -0,0 +1,66 @@
+---
+description: >
+  Benchmark one session (or a small recent set) against the rolling average using
+  Agent Monitor data — cost, total tokens, tool count, and workflow complexity
+  score — and report where each metric lands as a percentile of the population.
+  Tells you whether a session was normal, cheap, or an outlier. Use when judging
+  whether a session was typical or out of band.
+---
+
+# Benchmark
+
+Score a session against the rolling population average and report its percentile on
+cost, tokens, tool count, and complexity using Agent Monitor data.
+
+## Input
+
+The user provides: **$ARGUMENTS**
+
+This may be:
+- A single session ID — benchmark that session
+- "latest" — benchmark the most recent session
+- "latest N" — benchmark the N most recent sessions, each vs the average
+- empty — benchmark the most recent session (default)
+
+## Data Sources
+
+| Endpoint | Returns |
+|----------|---------|
+| `GET /api/sessions?limit=N` | Population of sessions with `cost`, `model`, `started_at`, `metadata` (turn_count, total_turn_duration_ms) — builds the rolling baseline |
+| `GET /api/pricing/cost/{sessionId}` | `{ total_cost, breakdown:[{ input_tokens, output_tokens, cache_read_tokens, cache_write_tokens, cost }] }` — the target session's cost and tokens |
+| `GET /api/workflows/{sessionId}` | `complexity` (score), `stats` (tool/event counts), `toolFlow` (distinct tools used) — the target session's tool count and complexity |
+| `GET /api/analytics` | `avg_events_per_session`, `tool_usage`, `daily_sessions` — corroborates population-level averages |
+
+## Report Sections
+
+### 1. Build the Baseline
+Fetch the population with `GET /api/sessions?limit=200` (the rolling set). For each
+session gather cost (`GET /api/pricing/cost/{id}` or the list `cost` field), total
+tokens (sum of the 4 token types from the pricing breakdown), tool count and
+complexity (`GET /api/workflows/{id}`). Compute mean, median, and standard
+deviation for each metric across the population.
+
+### 2. Measure the Target
+For the requested session, pull the same four metrics:
+- **Cost** — `total_cost` from `GET /api/pricing/cost/{id}`.
+- **Total tokens** — `input + output + cache_read + cache_write` summed from the breakdown.
+- **Tool count** — distinct/total tools from `GET /api/workflows/{id}` `stats`/`toolFlow`.
+- **Complexity score** — `complexity.score` from `GET /api/workflows/{id}`.
+
+### 3. Percentile and Deviation
+For each metric report the target's percentile within the population (share of
+sessions at or below it) and its z-score `(value − mean) / stddev`. Label each:
+below average / typical / above average / outlier (|z| > 2).
+
+### 4. Verdict
+State whether the session was normal overall. If it is an outlier, name which
+metric drove it (e.g., complexity p96, cost p91 → an unusually heavy session).
+
+## Output
+
+- A Markdown table: metric | session value | population mean | percentile | z-score | label.
+- Currency in USD to 4 decimals; tokens and tool counts as integers; complexity to 2 decimals.
+- Use ▲ for above-average and ▼ for below-average vs the mean.
+- One-line verdict: "Normal session" or "Outlier — driven by <metric> (pNN)".
+- When benchmarking multiple sessions, one row block per session plus a summary line.
+- Read-only: percentiles come only from the fetched population; never fabricate the baseline.