feat(odin): Phase 2a read-only agentic assistant + tool-trace UI

- agentic chat loop (max 6 round-trips, budget re-checked between iterations)
  over 10 read-only, permission-delegated tools in src/services/ai-tools.ts
- persist assistant tool trace in ai_chat_messages.content_json (+ migration)
- consulted-tools chips in OdinThread; header now shows month spend only
  (budget cap hidden from the UI, server-side 402 guard unchanged)
- seed: ai.use permission; Settings exposes the ai permission module
- docs: REVIEW consolidation; deployment-guide.md superseded by docs/release.md

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/admin/components/odin/OdinChat.tsx

@@ -122,6 +122,7 @@ export default function OdinChat() {
         messagesData.messages.map((m) => ({
           role: m.role as "user" | "assistant",
           content: m.content,
+          tools: m.meta?.tools,
         })),
       );
       setReview([]);
@@ -148,6 +149,9 @@ export default function OdinChat() {
         messages: msgs.map((m) => ({
           role: m.role,
           content: m.content.slice(0, MAX_STORE),
+          ...(m.tools && m.tools.length > 0
+            ? { meta: { tools: m.tools } }
+            : {}),
         })),
       }),
     })
@@ -208,24 +212,8 @@ export default function OdinChat() {
     const files = attachments.map((a) => a.file);
     if (!text && files.length === 0) return;
 
-    // Guard: Odin is scoped to invoice processing only (for now). A text-only
-    // message makes NO AI call — it gets a canned reply locally, so open-ended
-    // chat can't burn API credits. The invoice path (attachments) runs normally.
-    // (Removing this guard re-enables the general /chat path below for Phase 2.)
-    if (files.length === 0) {
-      setTurns((t) => [
-        ...t,
-        { role: "user", content: text },
-        {
-          role: "assistant",
-          content:
-            "Momentálně umím zpracovat pouze přijaté faktury. Přiložte prosím fakturu (PDF) a já z ní načtu údaje k uložení.",
-        },
-      ]);
-      setInput("");
-      return;
-    }
-
+    // Phase 2a: text messages go to the agentic /chat endpoint (read-only
+    // tools over system data); attachments keep the invoice-extract path.
     setBusy(true);
     const prevTurns = turns;
 
@@ -301,14 +289,17 @@ export default function OdinChat() {
         const body = await res.json();
         if (!res.ok) throw new Error(body?.error || "Chyba AI");
         const reply: string = body.data.reply;
-        setTurns((t) => [...t, { role: "assistant", content: reply }]);
+        const tools: ChatTurn["tools"] = Array.isArray(body.data.tool_trace)
+          ? body.data.tool_trace
+          : undefined;
+        setTurns((t) => [...t, { role: "assistant", content: reply, tools }]);
         setInput("");
         // Create the conversation now (first successful message) and persist.
         const convId = await ensureActive();
         if (convId != null)
           persist(convId, [
             { role: "user", content: userContent },
-            { role: "assistant", content: reply },
+            { role: "assistant", content: reply, tools },
           ]);
         qc.invalidateQueries({ queryKey: ["ai", "usage"] });
       }
@@ -495,8 +486,7 @@ export default function OdinChat() {
               color="text.secondary"
               sx={{ flexShrink: 0, display: { xs: "none", sm: "block" } }}
             >
-              Utraceno: ${usage.month_spend_usd.toFixed(2)} / $
-              {usage.budget_usd.toFixed(2)}
+              Utraceno: ${usage.month_spend_usd.toFixed(2)}
             </Typography>
           )}
         </Box>

src/admin/components/odin/OdinThread.tsx

@@ -1,5 +1,6 @@
 import Box from "@mui/material/Box";
 import Typography from "@mui/material/Typography";
+import Chip from "@mui/material/Chip";
 import { motion, useReducedMotion, type Variants } from "framer-motion";
 import type { ChatTurn } from "./types";
 import OdinMark from "./OdinMark";
@@ -197,6 +198,23 @@ export default function OdinThread({
                 bgcolor: isUser ? "primary.main" : "background.paper",
               }}
             >
+              {/* Tools the assistant consulted for this turn (Phase 2a). */}
+              {!isUser && t.tools && t.tools.length > 0 && (
+                <Box
+                  sx={{ display: "flex", flexWrap: "wrap", gap: 0.5, mb: 0.75 }}
+                >
+                  {t.tools.map((tool, j) => (
+                    <Chip
+                      key={`${tool.name}-${j}`}
+                      size="small"
+                      label={`🔍 ${tool.label}`}
+                      color={tool.ok ? "default" : "warning"}
+                      variant="outlined"
+                      sx={{ fontSize: "0.7rem", height: 22 }}
+                    />
+                  ))}
+                </Box>
+              )}
               {/* Color MUST sit on the Typography: GlobalStyles pins `p` to
                   text.secondary, which beats a color merely inherited from the
                   Box. An sx class on the element wins over that element rule. */}

src/admin/components/odin/types.ts

@@ -1,6 +1,14 @@
+export interface ToolTraceEntry {
+  name: string;
+  label: string;
+  ok: boolean;
+}
+
 export interface ChatTurn {
   role: "user" | "assistant";
   content: string;
+  /** Read-only tools the assistant called while producing this turn. */
+  tools?: ToolTraceEntry[];
 }
 
 export interface ReviewInvoice {