fix(stats): track ImageGen / VideoGen costs in usage insights (#13)

Before this, only chat LLM calls flowed through `recordUsage()`. The
ImageGen and VideoGen tools wrote to the content library but never
reported to the global stats file, so:

- `franklin insights` undercounted total 30-day spend by the exact
  amount spent on image + video generation.
- The "Top models" breakdown never surfaced `openai/gpt-image-1`,
  `bytedance/seedance-2.0`, `xai/grok-imagine-video`, etc. even when
  they were the dominant cost in a session.
- Monthly projections in insights were similarly low.

On successful generation each tool now fires a fire-and-forget
`recordUsage(model, 0, 0, costUsd, 0)`. Input/output tokens stay at 0
because image/video models don't bill by token; the cost is pulled
from the live gateway catalog via `findModel` + `estimateCostUsd`, the
same path the AskUser cost preview uses. When the catalog lookup fails
the tools fall back to hardcoded estimates so stats still get an
entry (under-approximate rather than missing).

The stats write is intentionally fire-and-forget and error-swallowing:
a `~/.blockrun/stats.json` write failure must not turn a paid generation
into a user-visible error.

Scope is deliberately small — only the two tools, +33 lines, zero
schema or behavior change to the existing tracker / insights engine.
Any record already written by chat flows continues to work unchanged.

Author: KillerQueen-Z

src/tools/imagegen.ts

@@ -22,6 +22,8 @@ import type { ContentLibrary } from '../content/library.js';
 import { checkImageBudget, recordImageAsset } from '../content/record-image.js';
 import { ModelClient } from '../agent/llm.js';
 import { analyzeMediaRequest, renderProposalForAskUser } from '../agent/media-router.js';
+import { recordUsage } from '../stats/tracker.js';
+import { findModel, estimateCostUsd } from '../gateway-models.js';
 
 interface ImageGenInput {
   prompt: string;
@@ -360,6 +362,20 @@ function buildExecute(deps: ImageGenDeps) {
     const sizeKB = (fileSize / 1024).toFixed(1);
     const revisedPrompt = imageData.revised_prompt ? `\nRevised prompt: ${imageData.revised_prompt}` : '';
 
+    // Stats: record this generation so it shows up in `franklin insights`
+    // alongside chat spend. Before this, media generations bypassed
+    // recordUsage entirely (only LLM chat calls were tracked), so the
+    // insights panel under-reported total spend and never surfaced
+    // image-generation models in its "top models" list. Fire-and-forget —
+    // stats write must not fail a user-visible generation.
+    void (async () => {
+      try {
+        const m = await findModel(imageModel);
+        const estCost = m ? estimateCostUsd(m, { quantity: 1 }) : 0;
+        recordUsage(imageModel, 0, 0, estCost, 0);
+      } catch { /* ignore stats errors */ }
+    })();
+
     let contentSummary = '';
     if (contentId && deps.library) {
       const rec = recordImageAsset(deps.library, {

src/tools/videogen.ts

@@ -37,6 +37,8 @@ import { loadConfig } from '../commands/config.js';
 import type { ContentLibrary } from '../content/library.js';
 import { ModelClient } from '../agent/llm.js';
 import { analyzeMediaRequest, renderProposalForAskUser } from '../agent/media-router.js';
+import { recordUsage } from '../stats/tracker.js';
+import { findModel, estimateCostUsd } from '../gateway-models.js';
 
 interface VideoGenInput {
   prompt: string;
@@ -351,6 +353,21 @@ function buildExecute(deps: VideoGenDeps) {
       const sizeMB = (fileSize / 1_048_576).toFixed(1);
       const dur = videoData.duration_seconds ?? duration;
 
+      // Stats: record this generation so it shows up in `franklin insights`
+      // alongside chat spend. Before this, media generations bypassed
+      // recordUsage entirely, so the insights panel under-reported total
+      // spend and never surfaced video models in its "top models" list.
+      // Prefer the live gateway price when the model is in the catalog;
+      // fall back to the legacy $0.05/s estimate otherwise. Fire-and-
+      // forget — stats write must not fail a user-visible generation.
+      void (async () => {
+        try {
+          const m = await findModel(videoModel);
+          const estCost = m ? estimateCostUsd(m, { duration_seconds: dur }) : estimateVideoCostUsd(dur);
+          recordUsage(videoModel, 0, 0, estCost, 0);
+        } catch { /* ignore stats errors */ }
+      })();
+
       let contentSummary = '';
       if (contentId && deps.library) {
         const rec = deps.library.addAsset(contentId, {