feat: per-tool settings, persistent settings file, Codex and Antigravity sessions, tokens and hooks (#40 B, C1, C2, D)

Part B: Model Pricing, Hook Configuration and CLAUDE_HOME move from
Settings → Dashboard to the Claude Code tab's AgentHub sub-tab
(ClaudeAgentHubSettings.tsx); CODEX_HOME is editable in Codex → AgentHub.
A home that is or contains the OS home is refused (EBADHOME).

Settings persistence: dashboard-saved settings go to
~/.config/agenthub/settings.env (AGENTHUB_SETTINGS_FILE), outside the plugin
cache an update wipes. Load order: real env > the checkout's .env > that file.
The first CLAUDE_HOME change pins DASHBOARD_DATA_DIR so the DB stays put.

C1: codex-usage.js reads Codex rollout journals into sessions (new column
tool) and token_usage, tracked per file in codex_rollouts; forks deduped by
total vector, sub-agent threads folded into the root; pricing-sync also
prices OpenAI models; PricingSettings with a vendor filter.

C2: codex-hooks.js installs AgentHub's hooks into $CODEX_HOME/hooks.json on
a click, through a stable forwarder; Codex trust is never written. The hook
route creates tool='codex' sessions and folds sub-agent hooks into the root.

D: antigravity-usage.js reads agy's per-conversation SQLite files (tokens
from ModelUsageStats) into tool='antigravity' sessions; antigravity-hooks.js
installs the named hook `agenthub` (PreInvocation, PostToolUse, Stop — never
PreToolUse) into ~/.gemini/config/hooks.json; Settings → Antigravity tab;
Gemini pricing.

Whole-change review fixes: sameOriginGuard on both home PUTs, routers.missing
on a CLAUDE_HOME change, reset-pricing scope, GET /api/sessions?tool=,
clear-data covering the new tables, Codex child-thread events moving no
status, hooks owning status only while current, EFOREIGN for a forwarder
that is not ours, agy quiet window and turn rules, AGENTHUB_SETTINGS_FILE
honoured from .env.

Docs, OpenAPI and the CLAUDE.md marker updated. Server 2141, client 779.

README.md

@@ -222,13 +222,35 @@ agenthub lanes add --repo /path/to/repo --slug my-feature      # managed worktre
 Every lane also carries the CLI that drives it — `claude` (the default) or
 `codex` — picked in the Add-lane modal and fixed for the life of the lane. A
 Codex lane's run panel offers Codex's own sandbox, approval and reasoning-effort
-choices, and resumes with `codex resume --last`. Codex emits none of this
-dashboard's hooks, so a Codex lane records its runs but stays absent from
-Sessions and Analytics. A Codex lane also carries **no pipeline** — no stage,
-no pipeline map, nothing inferred or advanced; the dashboard only mirrors its
-running/idle status from Codex's own rollout journals on disk
-(`$CODEX_HOME/sessions/**/rollout-*.jsonl`, polled every
-`DASHBOARD_CODEX_POLL_MS` ms, default 15000).
+choices, and resumes with `codex resume --last`. Codex sessions and token usage
+are read from Codex's own rollout journals: every Codex session (a lane's or
+not) appears in Sessions with a **Codex** badge and is priced like any other,
+with OpenAI rates filled in automatically (Settings → Codex → AgentHub). For a
+live feed, install **Codex hooks** from the same tab: the next time Codex starts
+it asks you to trust them (**Trust all and continue**), and from then on each
+tool call lands in the session's timeline, a codex lane turns running/idle as
+each turn starts and ends, and "Codex needs your permission" shows on the lane
+card and as a notification while Codex waits for an approval. A Codex lane also
+carries **no pipeline** — no stage, no pipeline map, nothing inferred or
+advanced; without hooks the dashboard mirrors its running/idle status from the
+rollout journals on disk (`$CODEX_HOME/sessions/**/rollout-*.jsonl`, polled
+every `DASHBOARD_CODEX_POLL_MS` ms, default 15000).
+
+An **Antigravity** lane runs Antigravity's `agy` CLI. Its sessions and token
+usage are read from agy's own conversation files
+(`~/.gemini/antigravity-cli/conversations/<id>.db`, every
+`DASHBOARD_ANTIGRAVITY_POLL_MS` ms, default 15000): every agy CLI session
+appears in Sessions with an **Antigravity** badge, priced with Gemini rates that
+are filled in automatically (Settings → Antigravity). **Antigravity hooks**, in
+the same tab, add a live feed: each tool call in the session's timeline and a
+lane that turns running/idle as a run starts and ends. agy asks for no trust,
+and it has no hook for a permission prompt, so an Antigravity lane never shows
+"needs your permission". agy fires no hook when it exits, nor when a run ends
+on an API error or a permission refused in headless mode, so a session gone
+quiet is marked completed and its lane set idle — after ten minutes of quiet
+for a session the hooks report on (a long tool call writes nothing, and after a
+Stop agy may still be waiting for you), after two minutes for one without
+hooks. Antigravity lanes carry no pipeline either.
 
 **Pipelines are dormant.** AgentHub ships no pipeline template, so a lane has no
 stages until you drop a template JSON into `DASHBOARD_PIPELINES_DIR` (see