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-productivity/skills/sprint-summary/SKILL.md

@@ -0,0 +1,77 @@
+---
+description: >
+  Summarize a sprint's worth of Claude Code activity — sessions grouped by
+  project (cwd), per-model cost breakdown, token efficiency (cache hit rate,
+  compaction baselines), subagent effectiveness from workflow API, velocity
+  metrics (turn_count, turn_duration_ms), and tool diversity across the sprint.
+---
+
+# Sprint Summary
+
+Generate a sprint summary from AgentHub data.
+
+## Input
+
+The user provides: **$ARGUMENTS**
+
+This may be:
+- A sprint duration: "last 2 weeks", "last 10 days"
+- A date range: "2025-03-31 to 2025-04-13"
+- "current sprint" (default: last 14 days)
+
+## Procedure
+
+1. **Fetch sprint data** from `http://localhost:4820`:
+   - `GET /api/sessions?limit=500` — all sessions in range (default sort: most recently updated first)
+   - `GET /api/analytics` — aggregated metrics
+   - `GET /api/pricing/cost` — total costs
+   - For high-value sessions: `GET /api/events?session_id={id}` — event details
+
+2. **Compile sprint summary**:
+
+   ### 🎯 Sprint Overview
+   - Sprint period: [start] to [end]
+   - Total sessions: N (completed: N, errored: N, abandoned: N)
+   - Total development hours with Claude Code: N
+   - Total cost: $X.XX
+   - Overall completion rate: N%
+
+   ### 📦 Deliverables
+   Group sessions by working directory (project):
+   - **Project A** (`/path/to/project`)
+     - N sessions, N hours, key activities
+   - **Project B** (`/path/to/other`)
+     - N sessions, N hours, key activities
+
+   ### 📊 Velocity Metrics
+   | Metric | Sprint | Previous Sprint | Trend |
+   |--------|--------|-----------------|-------|
+   | Sessions/day | N | N | ↑/↓ |
+   | Avg session duration | Nm | Nm | ↑/↓ |
+   | Cost/session | $N | $N | ↑/↓ |
+   | Tokens/session | N | N | ↑/↓ |
+   | Completion rate | N% | N% | ↑/↓ |
+
+   ### 🛠 Technology Breakdown
+   - Models used with distribution percentages
+   - Top 15 tools by usage with category grouping
+   - Subagent utilization rate
+
+   ### ⚡ Efficiency Analysis
+   - Token efficiency: cache hit rate, compaction frequency
+   - Cost per completed task
+   - Time-to-first-output (avg across sessions)
+   - Error recovery rate (sessions that recovered from errors)
+
+   ### 🔄 Retrospective Data Points
+   - **What went well**: Highest-efficiency sessions, best completion rates
+   - **What could improve**: Most expensive sessions, highest error rates
+   - **Action items**: Data-driven suggestions for next sprint
+
+## Output Format
+
+Professional sprint report suitable for sharing with team leads or managers:
+- Executive summary paragraph (5 sentences max)
+- Structured data tables with trend indicators
+- Grouped deliverables by project
+- Numbered action items at the end