feat(lsp): client-side LSP toolkit with 5 tools + integration tests

LSP client (lsp/client.rs):
- JSON-RPC framing over subprocess stdio
- Async request/response with oneshot channels
- Background read loop routing responses to pending requests
- 30s timeout per request, graceful shutdown

LSP manager (lsp/manager.rs):
- Auto-detect: Cargo.toml → rust-analyzer, package.json → tsserver,
  pyproject.toml → pyright, go.mod → gopls
- Initialize handshake, lazy textDocument/didOpen
- High-level methods: definition, references, hover, document_symbols,
  workspace_symbols
- Graceful degradation when binary not on PATH

LSP tools (tools.rs):
- lsp_definition, lsp_references, lsp_hover, lsp_diagnostics, lsp_symbols
- execute_lsp() async dispatch, is_lsp_tool() check
- All routed as ToolSide::Client in orchestrator

Tool schemas registered in Sol's build_tool_definitions() for Mistral.

Integration tests (6 new):
- Language detection for Rust project
- is_lsp_tool routing
- LSP initialize + hover on src/main.rs
- Document symbols (finds main function)
- Workspace symbols with retry (waits for rust-analyzer indexing)
- Graceful degradation with bad project path

Cargo.lock

@@ -379,6 +379,12 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "bitflags"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
+
 [[package]]
 name = "bitflags"
 version = "2.11.0"
@@ -696,7 +702,7 @@ version = "0.28.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "829d955a0bb380ef178a640b91779e3987da38c9aea133b20614cfed8cdea9c6"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "crossterm_winapi",
  "mio",
  "parking_lot",
@@ -1195,6 +1201,15 @@ dependencies = [
  "miniz_oxide",
 ]
 
+[[package]]
+name = "fluent-uri"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "17c704e9dbe1ddd863da1e6ff3567795087b1eb201ce80d8fa81162e1516500d"
+dependencies = [
+ "bitflags 1.3.2",
+]
+
 [[package]]
 name = "flurry"
 version = "0.5.2"
@@ -2165,7 +2180,7 @@ version = "0.1.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1744e39d1d6a9948f4f388969627434e31128196de472883b39f148769bfe30a"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "libc",
  "plain",
  "redox_syscall 0.7.3",
@@ -2225,6 +2240,19 @@ version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "112b39cec0b298b6c1999fee3e31427f74f676e4cb9879ed1a121b43661a4154"
 
+[[package]]
+name = "lsp-types"
+version = "0.97.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "53353550a17c04ac46c585feb189c2db82154fc84b79c7a66c96c2c644f66071"
+dependencies = [
+ "bitflags 1.3.2",
+ "fluent-uri",
+ "serde",
+ "serde_json",
+ "serde_repr",
+]
+
 [[package]]
 name = "matchers"
 version = "0.2.0"
@@ -2429,7 +2457,7 @@ version = "6.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "336b9c63443aceef14bea841b899035ae3abe89b7c486aaf4c5bd8aafedac3f0"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "libc",
  "once_cell",
  "onig_sys",
@@ -2913,7 +2941,7 @@ version = "0.13.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7c3a14896dfa883796f1cb410461aef38810ea05f2b2c33c5aded3649095fdad"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "getopts",
  "memchr",
  "pulldown-cmark-escape",
@@ -3091,7 +3119,7 @@ version = "0.29.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "eabd94c2f37801c20583fc49dd5cd6b0ba68c716787c2dd6ed18571e1e63117b"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "cassowary",
  "compact_str",
  "crossterm",
@@ -3126,7 +3154,7 @@ version = "0.5.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ed2bf2547551a7053d6fdfafda3f938979645c44812fbfcda098faae3f1a362d"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
 ]
 
 [[package]]
@@ -3135,7 +3163,7 @@ version = "0.7.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6ce70a74e890531977d37e532c34d45e9055d2409ed08ddba14529471ed0be16"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
 ]
 
 [[package]]
@@ -3307,7 +3335,7 @@ dependencies = [
  "aes",
  "aes-gcm",
  "async-trait",
- "bitflags",
+ "bitflags 2.11.0",
  "byteorder",
  "cbc",
  "chacha20",
@@ -3413,7 +3441,7 @@ version = "2.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3bb94393cafad0530145b8f626d8687f1ee1dedb93d7ba7740d6ae81868b13b5"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "bytes",
  "chrono",
  "flurry",
@@ -3466,7 +3494,7 @@ version = "0.38.44"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fdb5bc1ae2baa591800df16c9ca78619bf65c0488b41b96ccec5d11220d8c154"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "errno",
  "libc",
  "linux-raw-sys 0.4.15",
@@ -3479,7 +3507,7 @@ version = "1.1.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b6fe4565b9518b83ef4f91bb47ce29620ca828bd32cb7e408f0062e9930ba190"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "errno",
  "libc",
  "linux-raw-sys 0.12.1",
@@ -3667,7 +3695,7 @@ version = "2.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "897b2245f0b511c87893af39b033e5ca9cce68824c4d7e7630b5a1d339658d02"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "core-foundation 0.9.4",
  "core-foundation-sys",
  "libc",
@@ -3680,7 +3708,7 @@ version = "3.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b7f4bc775c73d9a02cde8bf7b2ec4c9d12743edf609006c7facc23998404cd1d"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "core-foundation 0.10.1",
  "core-foundation-sys",
  "libc",
@@ -3773,6 +3801,17 @@ dependencies = [
  "zmij",
 ]
 
+[[package]]
+name = "serde_repr"
+version = "0.1.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "175ee3e80ae9982737ca543e96133087cbd9a485eecc3bc4de9c1a37b47ea59c"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "serde_spanned"
 version = "0.6.9"
@@ -4067,6 +4106,7 @@ dependencies = [
  "crossbeam-channel",
  "crossterm",
  "futures",
+ "lsp-types",
  "ratatui",
  "rustls",
  "serde",
@@ -4085,6 +4125,7 @@ dependencies = [
  "tree-sitter-rust",
  "tree-sitter-typescript",
  "tui-markdown",
+ "url",
 ]
 
 [[package]]
@@ -4576,7 +4617,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d4e6559d53cc268e5031cd8429d05415bc4cb4aefc4aa5d6cc35fbf5b924a1f8"
 dependencies = [
  "base64",
- "bitflags",
+ "bitflags 2.11.0",
  "bytes",
  "futures-util",
  "http",
@@ -5011,7 +5052,7 @@ version = "0.244.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "47b807c72e1bac69382b3a6fb3dbe8ea4c0ed87ff5629b8685ae6b9a611028fe"
 dependencies = [
- "bitflags",
+ "bitflags 2.11.0",
  "hashbrown 0.15.5",
  "indexmap",
  "semver",
@@ -5530,7 +5571,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9d66ea20e9553b30172b5e831994e35fbde2d165325bec84fc43dbf6f4eb9cb2"
 dependencies = [
  "anyhow",
- "bitflags",
+ "bitflags 2.11.0",
  "indexmap",
  "log",
  "serde",