feat(web): Maple's alerts go through its bot - #373

🟢 Confidence 10/10 · safe to merge. Contained view/copy change; all four call sites of the reshaped helpers are updated and the scene test asserts both new alert links.
_{no findings · tests covered · risk low}

Splits the Maple alerts links off mapleIntegrationUrl into a new mapleAlertsUrl (/alerts?tab=routing) in both regions, updates the alerts-panel copy to say alerts go through the bot, and updates the scene test. Safe to merge.

• mapleIntegrationUrl no longer takes an entry and always opens chat-hazel
• euLink takes a full href, so alert and agent EU links share it
• Alerts panel copy and both alert CTAs point at Maple's alert routing

_{e24b1f7 · Reply "won't fix" to dismiss a finding, or mention @maple-review-bot to ask about one.}