feat: analytics parity — tool cost, date ranges, budgets, query explorer, replay, snapshots (v2.4.0)

Analytics parity phases 2–7 (docs/plans/analytics-parity/), built on
138e706 and ported onto v2.3.1:
- Cost by AI tool (?tool= on cost/analytics/stats/workflows, by_tool,
  Codex fast/priority and flex tiers, agenthub_cost_usd_total{tool,model})
- Date ranges (from/to) on cost/analytics/workflows; Analytics range select
  with Today / This week (Monday) / This month (1st) / 7d / 30d / 90d / All /
  Custom; workflow filters carried into workflow-stats.js (read worker)
- Budgets and cost alerts as alert rule types (alert_rules rebuilt without
  its rule_type CHECK), GET /api/budgets/status, rule preview, spend pace,
  status-bar budget chip; rules stay editable in place
- Query Explorer (/query, allowlisted sort, CSV/JSON export) and scheduled
  reports (report_definitions/report_runs, Settings → Reports)
- Session Replay tab and immutable snapshots (session_snapshots, /snapshot/:token)
- Remote Codex sync, push ingest with a hashed token, privacy redaction and
  ignored folders (Settings → Data), Cursor sessions (no cost)
- Read-only MCP server, statusline, Grafana/Prometheus files

Also: resizable sidebar, pet run/wave animations, the workspace home keeps a
half-typed prompt, and the pre-commit hook runs only the related tests for a
small commit.

.env.example

@@ -131,6 +131,20 @@
 # liveness/stale sweeps (which skip them). (default: 600000 = 10min).
 #   DASHBOARD_REMOTE_ACTIVE_WINDOW_MS=600000
 
+# ── Privacy and push ingest (Settings → Data) ────────────────────────────────
+# All three are normally saved from Settings into the settings file; set here,
+# they are pinned and the Settings page shows them read-only.
+# Redact secrets (API keys, tokens, bearer headers, private keys, password=…)
+# from stored event payloads and summaries: 1 = on (default: off).
+#   AGENTHUB_REDACT_SECRETS=1
+# Folders whose hooks are dropped whole (and skipped by the history import and
+# the Codex reader) — absolute paths, ':'-separated (';' on Windows); a folder
+# and everything under it.
+#   AGENTHUB_IGNORE_CWD=/home/you/clients/secret:/home/you/private
+# SHA-256 (hex) of the token POST /api/hooks/ingest-batch accepts. Unset = push
+# ingest off. Settings → Data → Push ingest makes the token and stores only this.
+#   AGENTHUB_PUSH_TOKEN_SHA256=
+
 # ── Lanes (durable parallel-work units and managed git worktrees) ────────────
 # Directory dashboard-managed worktrees are provisioned under. It is also the
 # boundary safety check 2 resolves every destructive lane path against: nothing