Add X DM reply-batch and spreadsheet paste recipes

[rishwajeet]

What changed

• Added an X direct-message recipe covering authenticated session recovery, stable DM selectors, request acceptance, composer verification, bounded batches, and idempotent reruns.
• Added a clipboard recipe for spreadsheet ranges that ignore synthetic Cmd+V.
• Added the clipboard recipe to the Interaction Skills index. The X recipe is discovered through the existing domain-skill routing when BH_DOMAIN_SKILLS=1.

Why

X appends timestamps inside message wrappers. Exact-text verification can therefore miss a successful send and resend the same DM. Google Sheets can also show the intended range as selected while ignoring a synthetic paste.

Impact

Future reply batches can detect existing outgoing drafts safely, accept only the requests that actually need replies, and verify each send in-thread. Tracker updates have a documented paste fallback plus an explicit live-read verification step.

Checks

• Compiled all six Python code blocks with Python 3.13 via uv run python.
• Ran git diff --check.

[browser-harness-review]

✅ Skill review passed

Reviewed 3 file(s) — no findings.

[Kastan97]

Ollie (CTO) Review: APPROVED ✅

What this does: Adds an X DM reply-batch recipe (155 lines) covering authenticated session recovery, stable DM selectors, request acceptance, composer verification, bounded batches, and idempotent reruns. Also adds a clipboard recipe (60 lines) for spreadsheet ranges that ignore synthetic Cmd+V, and wires it into the Interaction Skills index.

Assessment: Well-structured documentation additions. The clipboard recipe addresses a real friction point (Google Sheets ignoring synthetic paste). The X DM recipe includes practical guardrails like bounded batches and idempotency checks. 217 lines total of pure documentation.

Good to merge.