fix: improve inject prompt to guide users on /exec host switching

fix: bump version to 0.3.1 + clarify SSH key prompt

fix: clarify SSH key prompt to prevent AI from SSH-ing remotely

fix(ci): fix CI check failures on frontend lint and backend build

chore: update Cargo.lock + SSH guide UX improvements

feat: add diagnostic log export button to activity log

feat: add export_diagnostics command with rfd file dialog

feat: add i18n keys for diagnostic export

docs: add diagnostic export implementation plan

docs: add diagnostic export design

feat: SSH key creation + connection failure guidance

fix: SSH key selector dropdown + flush config before connect

feat: wire ProfileWizard into ConnectionPage

feat: add ProfileWizard 3-step component

feat: add i18n keys for connection wizard