refactor: rename plugin features with type prefix for consistency

- Plugin features now use type_ prefix (meta_magic, filter_grep, etc.)
- Added meta_all_musl and filter_all_musl for MUSL-compatible builds
- grep filter plugin made optional via filter_grep feature flag
- Removed regex crate from grep-related code, uses strip_prefix instead
- Updated CHANGELOG.md with breaking change documentation

CHANGELOG.md

@@ -9,6 +9,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- New `filter_grep` feature to optionally include the grep filter plugin (regex-based line filtering). Disabling this feature removes the `regex` crate and its ~800 KiB dependency stack from the binary.
+- New `meta_all_musl` feature for all MUSL-compatible meta plugins (excludes `meta_magic` which requires libmagic)
+- New `filter_all_musl` feature for all MUSL-compatible filter plugins
 - Database index on `items(ts)` column for faster ORDER BY sorting
 - Server API `ItemInfo` now includes `file_size` — actual filesystem-reported size of the item data file
 
@@ -23,6 +26,17 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Removed `once_cell` crate (replaced with `std::sync::LazyLock` from Rust 1.80)
 - Removed `lazy_static` crate (replaced with `std::sync::LazyLock`)
 
+### Breaking
+
+- Plugin feature flags renamed with type prefix for consistency:
+  - `magic` → `meta_magic`
+  - `infer` → `meta_infer`
+  - `tree_magic_mini` → `meta_tree_magic_mini`
+  - `tokens` → `meta_tokens`
+  - `grep` → `filter_grep`
+  - `all-meta-plugins` → `meta_all`
+  - `all-filter-plugins` → `filter_all`
+
 ### Fixed
 
 - CLI help text typo: "metatdata" → "metadata" in `--get` and `--info` descriptions