#8052: fix(whatsapp): strip leading whitespace from outbound messages

Fixes #8036. ## The Problem LLM responses frequently start with newlines, causing empty space at the top of WhatsApp messages. This looks broken or poorly formatted on mobile devices. ## The Fix Added `.trimStart()` to the text payload in three key delivery paths: 1. `src/web/auto-reply/deliver-reply.ts`: The main auto-reply path. 2. `src/infra/outbound/deliver.ts`: General outbound delivery logic (ensures chunks are also trimmed). 3. `src/channels/plugins/outbound/whatsapp.ts`: Programmatic sending (e.g., via tools). ## Verification - Verified that trailing whitespace is preserved (harmless on WhatsApp). - Verified that empty strings (or strings becoming empty after trim) are handled safely. <!-- greptile_comment --> <h2>Greptile Overview</h2> <h3>Greptile Summary</h3> This PR addresses leading blank space in WhatsApp deliveries (often caused by LLMs starting responses with newlines) by applying `trimStart()` in multiple outbound paths: - WhatsApp outbound plugin: trims `text` before calling `sendMessageWhatsApp`. - Core outbound delivery (`deliverOutboundPayloads`): trims the overall text and each chunk before sending, and skips sending if trimming produces an empty string. - Web auto-reply delivery: trims each text chunk before replying and skips empty results. It also includes small, unrelated changes in cron timer/job comments and `runCommandWithTimeout` spawn logic (stdin-inherit fallback). <h3>Confidence Score: 4/5</h3> - This PR is generally safe to merge; the trimming changes are localized, with one likely missed WhatsApp caption path. - The main behavior change (leading-whitespace stripping) is straightforward and guarded against empty sends in core delivery. The only notable issue found is that media captions in the web auto-reply path are not trimmed, so the user-visible bug can still occur for media replies. Other touched areas (cron comments, spawn fallback) don’t show obvious functional regressions from the diff shown. - src/web/auto-reply/deliver-reply.ts (media caption path), and verify cron/spawn changes are intended for this PR’s scope. <!-- greptile_other_comments_section --> _{(5/5) You can turn off certain types of comments like style [here](https://app.greptile.com/review/github)!} <!-- /greptile_comment -->