- Data flow is now strictly linear from `RawMatcher` to `Matcher`
- I've also hoisted `RawMatcher` in front of `Matcher` to signal this
- Re-type `RawMatcher.case_sensitive` from `bool` to `Option<bool>`
- This moves all parser logic away from `RawMatcher`, making it a more faithful representation of the data
- Favour default consts in `Matcher::try_from<RawMatcher>` to `Default` impl on `Case`
- Because the default choice of casing is a design decision of the logic, not an intrinsic property of the type
1. Added `Deserialize` derive and `#[serde(try_from = "RawMatcher")]` to the `Matcher` struct. With `try_from`, serde generates a `Deserialize` impl that first deserializes into `RawMatcher`, then calls `TryFrom<RawMatcher> for Matcher`. It never attempts to deserialize `Matcher`'s fields directly, so `Case` and `MatcherSegment` don't need `Deserialize` impls.
2. Replaced the manual `impl<'de> serde::Deserialize<'de> for Matcher` with a standard `impl TryFrom<RawMatcher> for Matcher`. The logic is identical - the conversion is fallible because `Matcher::from_str` returns `Result<_, anyhow::Error>`, so `try_from` (not `from`) is the correct choice, avoiding any panics.
The net effect: same behavior, same error handling, but using the idiomatic serde pattern instead of a manual deserializer impl. The `RawMatcher` intermediate type and its `#[serde(untagged)]` derive remain unchanged.
cyqsimon