fix: resolve all clippy warnings across codebase
Fix all clippy errors reported by `cargo clippy --all-targets -- -D warnings`
on Rust 1.93, covering both the original codebase and upstream dev changes.
Changes by category:
- format!() appended to String → write!/writeln! (telegram, discord)
- Redundant field names, unnecessary boolean not (agent/loop_)
- Long numeric literals (wati, nextcloud, telegram, gemini)
- Wildcard match on single variant (security/leak_detector)
- Derivable Default impls (config/schema)
- &Option<T> → Option<&T> or allow (config/schema, config/mod, gateway/api)
- Identical match arms merged (gateway/ws, observability, providers, main, onboard)
- Cast truncation allowed with rationale (discord, lark)
- Unnecessary borrows/returns removed (multiple files)
- Unused imports removed (channels/mod, peripherals/mod, tests)
- MSRV-gated APIs allowed locally (memory/hygiene, tools/shell, tools/screenshot)
- Unnecessary .get().is_none() → !contains_key() (gemini)
- Explicit iteration → reference loop (gateway/api)
- Test-only: useless vec!, field_reassign_with_default, doc indentation
Validated: cargo fmt, cargo clippy --all-targets -- -D warnings, cargo test
Co-authored-by: Cursor <cursoragent@cursor.com>
(cherry picked from commit 49e90cf3e4)
931cf40636