Add wallet-funded database creation and cycles flow

[humandebri]

Summary

• Add OISY and Plug wallet controls to the dashboard header, including disconnect support from the same connected wallet buttons.
• Require a connected wallet with enough KINIC before creating a database, then run the initial 1 KINIC cycles purchase immediately after the pending database is created.
• Simplify database cycles so the CLI prints and opens the browser funding URL without a KINIC argument, CLI identity, or canister call.
• Move write-cycle availability checks to the canister API and update the /cycles page, pending/not-active copy, CLI docs, and payment docs around the new funding flow.
• Consolidate admin navigation with AdminHeader, refresh dashboard/Skill Registry/document pane headers, and add database rename affordances in the dashboard.

Testing

• npm run test
• npm run typecheck
• Playwright checks for the dashboard header, create database dialog, and /cycles?database_id=db_test