fix(chat-swarm-runtime): submit prompts through CDP input

[James3014]

Wave 4 live G2 on #117 reproduced a false-positive send acknowledgement in the managed CDP carrier. The runtime entered waitForConversationUrl() even though the fresh Project target remained on the Project URL and the CDP target census contained no conversation created after the fresh Swarm timestamp. The remaining synthetic seam was button.click(): invoking it was treated as successful delivery without a physical conversation effect.

This change keeps the existing CdpMacWebDriver, exact-target identity fences, Swarm durable authority, and waitForConversationUrl() acknowledgement. It only replaces DOM button.click() with exact-target CDP mouse press/release at the visible enabled send button center. The regression tests require the native CDP mouse events for both editable and textarea composer paths and explicitly reject reintroducing button.click().

Candidate 69fb12827469e825f13d14f4ee833376884afc85 is based on deployed main@1cb8b42785f40fb8a023872e209155a948fa1088 and changes only src/chat-swarm-runtime.ts and src/chat-swarm-runtime.test.ts. git diff --check passes. Local dependency-backed verification is blocked by the current paired-carrier gate, so exact-head GitHub CI is the dependency-backed verifier before any live G2 rerun.