feat(whatsapp): bump whatsapp-rust 0.5 -> 0.6 with LID-native addressing

[juanlotito]

Summary

Bumps the whatsapp-rust family 0.5 → 0.6 and pins it to the merge commit of
oxidezap/whatsapp-rust#943 (DM LID-migration gate) via [patch.crates-io].

Why. whatsapp-rust 0.5 predates LID addressing. In practice that meant:

• Inbound: after WhatsApp migrated a peer's device registry PN → LID,
  Signal sessions desynced — Bad Mac / No session loops and PDO recovery
  floods that only a re-pair fixed.
• Outbound: DMs to @lid chats needed a local LID → PN rewrite hack in
  outbound.rs to be deliverable at all.

0.6 brings unified LID/PN addressing and migrates Signal sessions on LID
discovery, fixing both natively — the local rewrite hack is removed in this PR.

Why the rev pin. 0.6.0 alone regressed delivery for accounts the server
has not migrated to LID 1:1 (no lid_one_on_one_migration_enabled ab
prop): their LID-addressed DMs are silently 400-nacked (send() still returns
Ok). I hit this live, reported it in oxidezap/whatsapp-rust#941, and the fix
merged as oxidezap/whatsapp-rust#943 — the client now gates DM wire addressing
on the account's migration state automatically. No release includes it yet, so
the family is pinned to the #943 merge commit; the patch section documents that
it should collapse into a plain version bump on the next whatsapp-rust release.

Store/pairing work in this PR:

• Persisted Device records migrate in place through a 0.5-layout shim, so
  existing WhatsApp pairings survive the upgrade (postcard is not
  self-describing and 0.6 appended trailing fields — decoding old records with
  the new layout otherwise fails and forces a re-pair).
• Stores reworked for the 0.6 traits: typed [u8; 32] identities, Bytes
  sessions/prekeys, per-device sender-key tracking (replaces SKDM recipient
  lists + forget marks), delete_devices.
• DeviceListRecord persists as JSON because its raw_id uses
  skip_serializing_if, which postcard cannot round-trip; device lists are
  cache and re-fetch on decode mismatch.
• send_message returns SendResult, upload takes UploadOptions,
  DevicePropsOverride builder, Arc<Event> handlers, Jid.user is
  CompactString.
• Toolchain nightly bump (0.6 uses if-let guards; the newer nightly also fixes
  a rustc query-depth ICE with matrix-sdk).

Validation

Completed

• cargo fmt --all -- --check
• cargo clippy -Z unstable-options --workspace --all-targets -- -D warnings
  (default features)
• cargo clippy -Z unstable-options -p moltis-whatsapp --all-features --all-targets -- -D warnings
• cargo nextest run --workspace (default features)
• Live validation on a real companion-device pairing (home-server deploy):
  pairing from the 0.5-era store survived the upgrade in place, inbound
  and outbound DMs verified, 3/3 test DMs to a LID-mapped peer delivered
  with Delivered receipts and zero nacks — on an account the server has
  not LID-migrated, i.e. the exact population feat(web-ui): hide voice buttons when stt/tts disabled in config #943 protects.

Remaining

• just lint / just test with --all-features — my local environment
  has no CUDA toolchain, so the cuda feature builds are left to CI
• ./scripts/local-validate.sh <PR> once the PR number exists

Manual QA

1. Run a gateway with an existing WhatsApp pairing created under 0.5 — it must
   connect without re-pairing (the shim migrates the persisted Device record
   on first read).
2. Send a DM from the paired account to a contact whose chat is LID-addressed;
   confirm a Delivered receipt arrives and no ack error=400 appears with
   RUST_LOG=whatsapp_rust=debug.
3. Have the contact reply; confirm the inbound message decrypts (no Bad Mac
   / No session).
4. Restart the gateway; confirm reconnect + no store decode warnings.

[greptile-apps]

Greptile Summary

This PR bumps whatsapp-rust from 0.5 to 0.6 and pins to the post-#943 merge commit, which adds native LID/PN unified addressing and fixes Signal session desyncs and silent 400 nacks on LID-addressed DMs. The local LID→PN rewrite hack in outbound.rs is removed.

• Store migration: LegacyDevice05 shim decodes old 0.5 postcard records and upgrades them in place; DeviceListRecord is persisted as JSON (not postcard) because its raw_id field uses skip_serializing_if; both paths include warn/debug logging from the previous review cycle.
• Trait rework: SledStore and MemoryStore implement the 0.6 trait surface — typed [u8; 32] identities, Bytes sessions/prekeys, per-device sender-key tracking, delete_devices, SendResult, and UploadOptions; comprehensive round-trip tests cover every new code path.
• Toolchain bump: nightly-2025-12-27 → nightly-2026-06-20 to support 0.6's if-let guards and fix a rustc query-depth ICE with matrix-sdk.

Confidence Score: 5/5

This PR is safe to merge — the store migration shim is correct, the LID-native addressing path has been live-validated, and all previous review feedback was incorporated.

The core migration path (LegacyDevice05 shim, JSON-persisted DeviceListRecord, dual decode with warn logging) is implemented correctly and backed by targeted unit tests. The outbound LID→PN hack removal is clean.

connection.rs warrants a follow-up once the Bot 0.6 destructor flush guarantee is confirmed — no other files require special attention.

Important Files Changed

Filename	Overview
crates/whatsapp/src/sled_store.rs	Major rewrite implementing 0.6 store traits; LegacyDevice05 migration shim with in-place upgrade; DeviceListRecord stored as JSON; warn/debug logging on both decode paths. Well-tested and previous review comments are fully addressed.
crates/whatsapp/src/connection.rs	Bot lifecycle migrated to the 0.6 select-on-cancel pattern; OnceCell state-ref wiring for the event handler. The pre-existing concern about whether dropping the bot future guarantees a sled flush before mark_done() remains unaddressed in code.
crates/whatsapp/src/outbound.rs	LID→PN rewrite hack removed; send_message now uses SendResult.message_id for self-chat loop detection; upload uses UploadOptions via Default::default(). Tests confirm JID resolution handles LID pass-through correctly.
crates/whatsapp/src/handlers.rs	Updated for Arc, CompactString Jid.user, and LID-aware owner detection using both PN and LID JIDs. Self-chat detection logic is sound and well-covered by tests.
crates/whatsapp/src/memory_store.rs	Reworked for 0.6 traits with typed identities, Bytes sessions, per-device sender-key tracking, and all new store methods. Comprehensive tests added.
Cargo.toml	Adds [patch.crates-io] block pinning the entire whatsapp-rust family to git rev 96686ea; bumps version constraints from 0.5 to 0.6; adds serde-big-array workspace dep. Patch comment explains the removal strategy.
rust-toolchain.toml	Toolchain bumped from nightly-2025-12-27 to nightly-2026-06-20 to support if-let guards used by 0.6 and to resolve a rustc ICE.
crates/whatsapp/src/state.rs	AccountState.send_message updated to use SendResult; watermark logic unchanged. ShutdownState and sent-ID tracking unaffected.

_{Reviews (2): Last reviewed commit: "fix(whatsapp): log device-store decode f..." | Re-trigger Greptile}