Rebuild Arti from audited source with enforced provenance

Vendored arti.xcframework rebuilt from source (Rust 1.96.0, normalized
archive metadata for reproducible hashes). New ARTI-BINARY-PROVENANCE.md
records toolchain, rebuild steps, and a SHA256 manifest for every file
in the xcframework. A new CI workflow turns that policy into a gate:
PRs must keep the binary matching the manifest, and binary changes must
ship with source/lockfile/build-script evidence.

Also raises TorManager.awaitReady's default timeout from 25s to 75s to
match the bootstrap monitor deadline - a shorter wait reported "not
ready" while Arti was still legitimately bootstrapping, silently
stranding queued relay work.

Privacy policy, Tor integration doc, and privacy assessment updated to
match the current implementation.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

PRIVACY_POLICY.md

@@ -1,6 +1,6 @@
 # bitchat Privacy Policy
 
-*Last updated: January 2025*
+*Last updated: June 2026*
 
 ## Our Commitment
 
@@ -9,7 +9,7 @@ bitchat is designed with privacy as its foundation. We believe private communica
 ## Summary
 
 - **No personal data collection** - We don't collect names, emails, or phone numbers
-- **No servers** - Everything happens on your device and through peer-to-peer connections
+- **No accounts or company servers** - Mesh chat works peer-to-peer; optional Nostr features use public or user-selected relays
 - **No tracking** - We have no analytics, telemetry, or user tracking
 - **Open source** - You can verify these claims by reading our code
 
@@ -17,11 +17,11 @@ bitchat is designed with privacy as its foundation. We believe private communica
 
 ### On Your Device Only
 
-1. **Identity Key** 
-   - A cryptographic key generated on first launch
+1. **Identity Keys**
+   - Cryptographic private keys generated on first launch or when optional Nostr identities are created
    - Stored locally in your device's secure storage
    - Allows you to maintain "favorite" relationships across app restarts
-   - Never leaves your device
+   - Private keys never leave your device; public keys are shared when needed for messaging
 
 2. **Nickname**
    - The display name you choose (or auto-generated)
@@ -38,12 +38,19 @@ bitchat is designed with privacy as its foundation. We believe private communica
    - Stored only on your device
    - Allows you to recognize these peers in future sessions
 
+5. **Optional Location Channel State**
+   - Your selected geohash channel, bookmarked geohashes, teleport flags, and bookmark display names
+   - Stored locally on your device so the location-channel UI can restore your choices
+   - Per-geohash Nostr identities are derived locally from a device seed stored in secure storage
+   - Exact latitude and longitude are not persisted by bitchat
+
 ### Temporary Session Data
 
 During each session, bitchat temporarily maintains:
 - Active peer connections (forgotten when app closes)
 - Routing information for message delivery
 - Cached messages for offline peers (12 hours max)
+- Your current location while optional location channels are enabled, used locally to compute geohash channels and friendly place names
 
 ## What Information is Shared
 
@@ -62,13 +69,21 @@ When you join a password-protected room:
 - Your nickname appears in the member list
 - Room owners can see you've joined
 
+### With Nostr Relays (Optional Features)
+
+If you enable Nostr-backed features:
+- Private fallback messages to mutual favorites are sent as encrypted NIP-17 gift wraps. Relays can see event metadata, but not message content.
+- Public location-channel messages, location notes, and presence are scoped with geohash tags. Relays and other participants can see the geohash tag, event kind, timestamp, and public key used for that geohash.
+- Exact GPS coordinates are not included in Nostr events by bitchat. The geohash precision you choose can still reveal an approximate area, from region-level to building-level.
+- Automatic presence heartbeats are limited to low-precision geohashes (region, province, and city). More precise geohash posts happen only when you use those channels or location notes.
+
 ## What We DON'T Do
 
 bitchat **never**:
 - Collects personal information
-- Tracks your location
-- Stores data on servers
-- Shares data with third parties
+- Sells or shares your exact GPS location
+- Stores data on servers we operate
+- Sells your data to advertisers or data brokers
 - Uses analytics or telemetry
 - Creates user profiles
 - Requires registration
@@ -84,19 +99,27 @@ All private messages use end-to-end encryption:
 ## Your Rights
 
 You have complete control:
-- **Delete Everything**: Triple-tap the logo to instantly wipe all data
-- **Leave Anytime**: Close the app and your presence disappears
-- **No Account**: Nothing to delete from servers because there are none
-- **Portability**: Your data never leaves your device unless you export it
+- **Delete Local State**: Triple-tap the logo to instantly wipe local keys, sessions, caches, and preferences
+- **Leave Anytime**: Close the app and local presence stops; relay-backed presence ages out
+- **No Account**: No account record exists for you to delete from us
+- **Portability**: Your local state stays on your device unless you send messages, use optional relay-backed features, or export it
 
 ## Bluetooth & Permissions
 
 bitchat requires Bluetooth permission to function:
 - Used only for peer-to-peer communication
-- No location data is accessed or stored
 - Bluetooth is not used for tracking
 - You can revoke this permission at any time in system settings
 
+## Location Permission
+
+Location permission is optional and is used only for location channels:
+- Used to compute local geohash channels and display names
+- Requested as when-in-use permission
+- Exact coordinates are not shared in messages or stored by bitchat
+- Selected and bookmarked geohashes may persist locally until you remove them, use panic wipe, or delete the app
+- You can revoke this permission at any time in system settings
+
 ## Children's Privacy
 
 bitchat does not knowingly collect information from children. The app has no age verification because it collects no personal information from anyone.
@@ -106,12 +129,15 @@ bitchat does not knowingly collect information from children. The app has no age
 - **Messages**: Deleted from memory when app closes (unless room retention is enabled)
 - **Identity Key**: Persists until you delete the app
 - **Favorites**: Persist until you remove them or delete the app
+- **Location channel choices**: Selected/bookmarked geohashes persist locally until removed, panic-wiped, or the app is deleted
+- **Nostr relay data**: Public geohash events and encrypted gift wraps may be retained by relays according to each relay's policy
 - **Everything Else**: Exists only during active sessions
 
 ## Security Measures
 
 - All communication is encrypted
-- No data transmitted to servers (there are none)
+- No accounts or company servers
+- Optional Nostr relays receive only the events needed for Nostr-backed private fallback or public location channels
 - Open source code for public audit
 - Regular security updates
 - Cryptographic signatures prevent tampering
@@ -121,7 +147,7 @@ bitchat does not knowingly collect information from children. The app has no age
 If we update this policy:
 - The "Last updated" date will change
 - The updated policy will be included in the app
-- No retroactive changes can affect data (since we don't collect any)
+- No retroactive changes can make us collect data already held only in your app
 
 ## Contact
 
@@ -132,7 +158,7 @@ bitchat is an open source project. For privacy questions:
 
 ## Philosophy
 
-Privacy isn't just a feature—it's the entire point. bitchat proves that modern communication doesn't require surrendering your privacy. No accounts, no servers, no surveillance. Just people talking freely.
+Privacy isn't just a feature—it's the entire point. bitchat proves that modern communication doesn't require surrendering your privacy. No accounts, no company servers, no analytics. Just people talking freely.
 
 ---