feat(events): add TimeoutKind to classify Error::Timeout by operation

[devin-ai-integration]

Summary

Error::Timeout was a unit variant that collapsed every *_and_wait deadline miss into one shape, so callers could not tell apart "login did not complete in time" from "file transfer stalled" without string-matching on the Display output. This PR introduces TimeoutKind, a #[non_exhaustive] enum with one variant per categorised blocking operation, and threads it through every internal construction site.

New API (teamtalk::events):

• TimeoutKind (#[non_exhaustive]) — Command, Connect, Login, Join, Transfer, ServerConfig, Other.
• TimeoutKind::name / Display — short stable lower-snake-case label for logs and metrics.
• Error::timeout(kind) — short constructor.
• Error::timeout_kind(&self) -> Option<TimeoutKind> — non-consuming accessor, returns Some(kind) only for Error::Timeout.
• Error::Timeout { kind: TimeoutKind } — struct variant (was unit). thiserror Display now formats as Operation timed out: <kind>.

Internal call-site mapping:

• client/core/runtime.rs::poll_command_completion → TimeoutKind::Command (propagates to wait_for_command, list_bans_and_wait, list_user_accounts_and_wait).
• client/users/auth.rs::login_and_wait → TimeoutKind::Login.
• client/channels.rs::join_channel_and_wait → TimeoutKind::Join.
• client/server.rs::update_server_and_wait, save_server_config_and_wait → TimeoutKind::Command (generic command completions; ServerConfig is available for future differentiation).
• client/users/directory.rs::create_user_account_and_wait, delete_user_account_and_wait → TimeoutKind::Command.
• client/files.rs::wait_for_file_transfer / wait_for_file_transfer_terminal → TimeoutKind::Transfer.

Breaking change note:

match err { Error::Timeout => .. } no longer matches as a unit variant; it is now

match err { Error::Timeout { kind } => .. }
// or
if let Some(kind) = err.timeout_kind() { .. }

Error is #[non_exhaustive], so downstream match arms already require a catch-all; the only code affected is code that was specifically matching the unit Timeout variant, which is rare and trivial to migrate. No tests or examples in this repository relied on the unit shape.

Tests: crates/teamtalk/tests/timeout_kind_tests.rs adds 9 integration cases — constructor, accessor on all kinds + all non-Timeout variants, Display contains the kind name and the base phrase, Display distinguishes kinds, name-is-snake-case-stable, Display matches name, names are unique, derived traits (Copy, Clone, Debug, Eq, Hash) are usable.

Local verification: cargo fmt --all --check clean; cargo clippy --workspace --all-targets --all-features -- -D warnings clean; cargo test --workspace --all-features — all existing tests pass plus 9 new TimeoutKind cases.

Review & Testing Checklist for Human

• Confirm the mapping of internal call sites to TimeoutKind values is what you want — in particular the update_server_and_wait / save_server_config_and_wait pair currently maps to TimeoutKind::Command (they are generic command waits); the ServerConfig kind is available if you'd prefer a dedicated classification.
• Confirm the breaking change on Error::Timeout (unit → struct variant) is acceptable. No in-repo code matched the unit shape, so the migration is trivial outside this crate.
• Confirm the TimeoutKind::Other escape hatch — added to keep future call sites from getting stuck on PR review over naming; #[non_exhaustive] means new named kinds can replace Other later without another breaking change.

Notes

Fourth P1 API improvement after ExponentialBackoff jitter (#51), StreamTypes newtype (#52), and SdkErrorCode typed mapping (#54). Branches from clean main, independent of the other open PRs, so can be merged in any order.

Next up: SecretString + zeroize for passwords in LoginParams, indexed EventBus::dispatch / Router::dispatch via HashMap, then a coverage-gap test fill-in driven by scripts/audit_teamtalk_coverage.py.

The pre-existing semver CI gate is expected to remain red; release-plz handles the eventual version bump.

Link to Devin session: https://app.devin.ai/sessions/71fdd6196cb74723a2e277bb81993a9c
Requested by: @BlindMaster24

---

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR. Add '(aside)' to your comment to have me ignore it.
• Look at CI failures and help fix them

Note: I can only respond to comments from users who have write access to this repository.

⚙️ Control Options:

• Disable automatic comment and CI monitoring