#10889: fix: pass fileName through WhatsApp document send path

Fixes #10862 ## Problem When sending documents via the tool/send path, `fileName` is hardcoded as `"file"` in `send-api.ts:43`. All WhatsApp document attachments show up as "file" regardless of actual filename. The auto-reply path (`deliver-reply.ts:138`) already handles this correctly — the tool-invoked path just never wired it through. ## Changes | File | Change | |------|--------| | `src/web/active-listener.ts` | Add `fileName?: string` to `ActiveWebSendOptions` | | `src/web/inbound/send-api.ts` | Use `sendOptions?.fileName \|\| "file"` instead of hardcoded `"file"` | | `src/web/outbound.ts` | Accept `fileName` in options, capture from `loadWebMedia()` result, pass through to `sendOptions` | | `src/web/outbound.test.ts` | Update document send test to expect `fileName` in `sendOptions` | ## How it works `loadWebMedia()` already returns `fileName` — it was just being discarded in `outbound.ts`. This PR threads it through the full chain: ``` loadWebMedia() → outbound.ts → ActiveWebSendOptions → send-api.ts → Baileys payload ``` `options.fileName` is initialized before the `mediaUrl` block so callers can explicitly set a filename even without media — addressing the scope issue from the previous review. 4 files, 11 lines changed. <!-- greptile_comment --> <h2>Greptile Overview</h2> <h3>Greptile Summary</h3> - Threads `fileName` through the WhatsApp Web outbound send path so document attachments don’t show up as the generic "file". - Extends `ActiveWebSendOptions` and `sendMessageWhatsApp` options to carry an optional `fileName`, defaulting to the media-derived name when present. - Updates the web send API to set Baileys document `fileName` from `sendOptions.fileName` (fallbacking to "file"). - Adjusts the outbound unit test to assert `fileName` is passed in the send options for document sends. <h3>Confidence Score: 5/5</h3> - This PR is safe to merge with minimal risk. - Changes are small and localized, thread an optional field through an existing call chain, and include an updated unit test assertion covering the new behavior. No behavioral changes for non-document media types beyond passing an extra optional option object when a filename is present. - No files require special attention <!-- greptile_other_comments_section --> _{(3/5) Reply to the agent's comments like "Can you suggest a fix for this @greptileai?" or ask follow-up questions!} **Context used:** - Context from `dashboard` - CLAUDE.md ([source](https://app.greptile.com/review/custom-context?memory=fd949e91-5c3a-4ab5-90a1-cbe184fd6ce8)) - Context from `dashboard` - AGENTS.md ([source](https://app.greptile.com/review/custom-context?memory=0d0c8278-ef8e-4d6c-ab21-f5527e322f13)) <!-- /greptile_comment -->