events dashboard baseline: /provider/:pk view + merged jurisdictions

[AquiGorka]

Summary

• Removes the "Events" nav link.
• Adds :param segment support to the hash router via getRouteParams().
• Replaces /pp, /dashboard, /events with a single /provider/:pk route that combines provider info (name, OpEx balance, jurisdictions, council, assets) with the realtime events live tail. Home row clicks navigate via URL — no more sessionStorage.selected_pp. Unknown pk → 404.
• Jurisdictions on both /home rows and /provider/:pk are computed from server-supplied data: merged council + provider for ACTIVE memberships, PP-claimed only for PENDING/REJECTED, localStorage fallback when there's no membership at all.
• Treasury endpoint now takes ppPublicKey (server requires it).
• Dev CSP allows ws://localhost:* so the events WebSocket can connect locally.
• Provider header gets an icon back-button matching council-console's pattern.

Branch note: the branch is still named fix/events-dashboard-remove-nav-link from the first commit. The scope grew during pairing — happy to rename if preferred.

Test plan

• deno task fmt --check, deno task lint, deno task check, deno task build, deno task test pass
• End-to-end via local-dev: /home → click PP → URL becomes #/provider/<pk> → page renders → events tail shows live activity when ./send-loop.sh is fired