feat(dart): add Dart/Pub ecosystem support

CHANGELOG.md

@@ -7,6 +7,14 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+- **Dart/Pub ecosystem support** — New `deps-dart` crate with full pubspec.yaml and pubspec.lock support
+  - YAML parser with position tracking via yaml-rust2
+  - pub.dev API client for package info and search
+  - pubspec.lock parser for installed version resolution
+  - Dart version constraint matching (caret, range, any, exact) with correct 0.x semantics
+  - Hosted, git, path, and SDK dependency sources
+
 ## [0.6.1] - 2026-02-16
 
 ### Added

Cargo.toml

@@ -21,6 +21,7 @@ deps-npm = { version = "0.6.1", path = "crates/deps-npm" }
 deps-pypi = { version = "0.6.1", path = "crates/deps-pypi" }
 deps-go = { version = "0.6.1", path = "crates/deps-go" }
 deps-bundler = { version = "0.6.1", path = "crates/deps-bundler" }
+deps-dart = { version = "0.6.1", path = "crates/deps-dart" }
 deps-lsp = { version = "0.6.1", path = "crates/deps-lsp" }
 futures = "0.3"
 insta = "1"
@@ -44,6 +45,7 @@ tower-lsp-server = "0.23"
 tracing = "0.1"
 tracing-subscriber = "0.3"
 urlencoding = "2.1"
+yaml-rust2 = "0.10"
 zed_extension_api = "0.7"
 
 [workspace.lints.rust]

crates/deps-dart/Cargo.toml

@@ -0,0 +1,33 @@
+[package]
+name = "deps-dart"
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+authors.workspace = true
+license.workspace = true
+repository.workspace = true
+description = "pubspec.yaml support for deps-lsp"
+publish = true
+
+[lints]
+workspace = true
+
+[dependencies]
+deps-core = { workspace = true }
+async-trait = { workspace = true }
+serde = { workspace = true, features = ["derive"] }
+serde_json = { workspace = true }
+thiserror = { workspace = true }
+tokio = { workspace = true, features = ["fs"] }
+tower-lsp-server = { workspace = true }
+tracing = { workspace = true }
+urlencoding = { workspace = true }
+yaml-rust2 = { workspace = true }
+
+[dev-dependencies]
+criterion = { workspace = true, features = ["html_reports"] }
+insta = { workspace = true, features = ["json"] }
+once_cell = { workspace = true }
+tempfile = { workspace = true }
+tokio = { workspace = true, features = ["macros", "rt-multi-thread"] }
+tokio-test = { workspace = true }