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.

server/openapi.js

@@ -241,6 +241,11 @@ function createOpenApiSpec() {
               description: "JSON-encoded session metadata",
             },
             updated_at: { type: "string", format: "date-time" },
+            tool: {
+              type: "string",
+              description:
+                "The AI coding CLI that produced the session: `claude` (Claude Code's hooks and imported transcripts), `codex` (Codex's rollout journals and its opt-in hooks) or `antigravity` (agy's conversation files and its opt-in hooks).",
+            },
             agent_count: { type: "integer", nullable: true },
             last_activity: { type: "string", format: "date-time", nullable: true },
             cost: { type: "number", nullable: true },
@@ -822,11 +827,18 @@ function createOpenApiSpec() {
             hook_type: {
               type: "string",
               description:
-                "Hook type from Claude Code (common values: PreToolUse, PostToolUse, Stop, SubagentStop, Notification, SessionStart, SessionEnd)",
+                "Hook type from the CLI that sent it (Claude Code: PreToolUse, PostToolUse, Stop, SubagentStop, Notification, SessionStart, SessionEnd; Codex adds PermissionRequest and Interrupt; agy sends PreInvocation, PostToolUse and Stop)",
+            },
+            tool: {
+              type: "string",
+              enum: ["claude", "codex", "antigravity"],
+              description:
+                "Which CLI sent the hook (`scripts/hook-handler.js <Event> [codex|antigravity]`). An allowlist: anything else is `claude`.",
             },
             data: {
               type: "object",
-              required: ["session_id"],
+              description:
+                "The raw hook payload. Claude Code and Codex name the session `session_id`; agy names it `conversationId` and is accepted only with a `transcriptPath` under its own CLI directory.",
               properties: {
                 session_id: { type: "string" },
                 tool_name: { type: "string" },
@@ -838,10 +850,19 @@ function createOpenApiSpec() {
         },
         HookEventResponse: {
           type: "object",
-          required: ["ok", "event"],
+          required: ["ok"],
           properties: {
             ok: { type: "boolean", enum: [true] },
             event: { $ref: "#/components/schemas/DashboardEvent" },
+            ignored: {
+              type: "boolean",
+              description:
+                "The hook maps to nothing AgentHub records (a Codex sub-agent's lifecycle hook, an agy event other than a turn's first PreInvocation, a PostToolUse or a Stop, or a hook from the Antigravity IDE).",
+            },
+            duplicate: {
+              type: "boolean",
+              description: "The same hook delivered twice within 10 seconds; stored once.",
+            },
           },
         },
         PricingRule: {