feat: add profile and contacts fetching from pubky

[ben-kaufman]

Summary

Integrates Pubky decentralized identity into Bitkit, allowing users to create a Bitkit-managed profile or connect via Pubky Ring authentication. Once connected, the user's profile name and avatar appear on the home screen header, a full profile page shows their bio, links, tags, and shareable QR code, and a contacts section lists people they follow on the Pubky network.

What's included

• Dual profile creation flow — create a new profile from BIP39 seed derivation, or import via Pubky Ring deep links (pubkyauth://)
• Profile restore — when creating a profile, if one already exists on the network for the derived keys, it is detected and pre-populated (name, bio, links, tags preserved)
• Ring auth import flow — after Ring authentication, discover existing profile and contacts from pubky.app, present import overview with "Import all" or "Select" options, then proceed to Pay Contacts onboarding
• Pay Contacts onboarding — new step after both create and Ring import flows, with toggle for sharing payment data
• Profile page displaying name, bio, links, tags, and a QR code with the profile picture overlaid
• Profile editing — edit name, bio, links, and tags with suggestion sheets for links and tags
• Contacts list with alphabetically grouped sections, search, add, edit, and delete
• Contact detail page showing name, truncated public key, bio, links, tags, and copy/share/edit/delete actions
• Contact import — overview screen showing found profile & contacts count with avatar stack, selection screen with select all/none, batch import
• Home screen integration showing the authenticated user's name and avatar in the header
• Session restoration — automatic re-sign-in using stored secret key when session import fails (Bitkit-managed); session preserved on failure for retry on next launch (Ring-managed); toast notification when restoration fails
• PubkyService — service layer wrapping paykit-ffi (profile/contacts/payments) and bitkit-core (auth relay, PKDNS file fetching, key derivation)
• PubkyProfileManager — manages auth state, session lifecycle, key derivation, profile creation/editing, and remote profile fetching
• ContactsManager — fetches contacts in parallel via withTaskGroup, groups alphabetically, supports add/edit/delete/import, discovers remote contacts from pubky.app
• PubkyImage component for loading pubky:// URIs with two-tier (memory + disk) caching
• PubkyProfileData backward-compatible decoding — tags field defaults to empty array when missing from JSON (older profiles, other clients)
• Suggestion card auto-dismiss when user is already authenticated
• QR component — moved QR code generation off the main thread

New dependencies

• paykit-rs (SPM, pinned revision) — Pubky SDK for profile, contacts, and payment operations
• CoreBluetooth framework (linker flag, required by paykit-rs)

Key new files

File	Purpose
Services/PubkyService.swift	FFI bridge to paykit-ffi and bitkit-core
Managers/PubkyProfileManager.swift	Auth state, session persistence, key derivation, profile CRUD
Managers/ContactsManager.swift	Contact fetching, import, add/edit/delete, remote discovery
Models/PubkyProfile.swift	Profile/contact data models with backward-compatible decoding
Models/PubkyAuthRequest.swift	Auth request capability parsing
Components/PubkyImage.swift	pubky:// image loader with disk+memory cache
Views/Profile/ProfileView.swift	Full profile page (name, bio, links, tags, QR)
Views/Profile/CreateProfileView.swift	Profile creation with restore detection
Views/Profile/EditProfileView.swift	Profile editing
Views/Profile/PayContactsView.swift	Pay Contacts onboarding step
Views/Profile/PubkyChoiceView.swift	Create vs Ring import choice
Views/Profile/PubkyRingAuthView.swift	Pubky Ring auth flow UI
Views/Profile/AddLinkSheet.swift	Add link with suggestions
Views/Profile/AddProfileTagSheet.swift	Add tag with suggestions
Views/Contacts/ContactsListView.swift	Grouped, searchable contacts list
Views/Contacts/ContactDetailView.swift	Contact detail with actions
Views/Contacts/ContactImportOverviewView.swift	Import overview (profile + contacts summary)
Views/Contacts/ContactImportSelectView.swift	Selectable contact list for import
Views/Contacts/AddContactView.swift	Add contact by public key
Views/Contacts/EditContactView.swift	Edit contact details
Views/Sheets/PubkyAuthApproval/PubkyAuthApprovalSheet.swift	Auth approval as authenticator
BitkitTests/PubkyModelTests.swift	Tests for profile/contact models and data decoding
BitkitTests/PubkyProfileManagerTests.swift	Tests for HomegateResponse decoding
BitkitTests/PubkyAuthRequestTests.swift	Tests for capability parsing

Test plan

• Fresh install: tap Profile in drawer → shows intro → continue → choice screen (Create / Import with Ring)
• Create flow: Create Profile → enter name, pick avatar → Continue → Pay Contacts → Profile page
• Create restore: If profile already exists for derived keys, name is pre-populated and title shows "Restore Profile"
• Ring flow: Import with Ring → opens Pubky Ring → approve → returns to Bitkit → Import Overview (found profile & contacts) → Import All or Select → Pay Contacts → Profile page
• Ring flow (no contacts): If no remote contacts found, skip import and go to Pay Contacts
• Import select: Can select all, select none, or pick individual contacts; Continue with none selected skips import
• Profile page shows name, bio, links, tags, QR code with profile picture overlay
• Edit profile: tap edit → modify name/bio/links/tags → save → updated
• Home header shows profile name and avatar after authentication
• Kill and relaunch app → session restored, profile/contacts shown without re-auth
• Kill and relaunch with no network → session preserved, toast shown, next launch with network restores
• Sign out from profile page → returns to unauthenticated state, contacts cleared
• Contacts list shows "My Profile" row, alphabetical sections, search, and add button
• Add contact by public key → fetches profile → saves
• Edit contact → modify details → save
• Delete contact → confirmation → removed
• Suggestion sheets for links and tags show lightbulb icon inside input field

🤖 Generated with Claude Code

[ovitrif]

LGTM with some nit comments.

all tests worked great, tested:

• open profile from topbar + drawer
• 2x auth successes
• button to download ring
• share pk button(s)
• signout button