scope project data directories by version

Each ClickHouse version now stores its data in `.clickhouse/{version}/`
instead of a shared `.clickhouse/` directory, preventing compatibility
issues when switching between versions with `chv use`.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: sdairs

Cargo.lock

@@ -1,6 +1,6 @@
 [package]
 name = "chv"
-version = "0.1.2"
+version = "0.1.3"
 edition = "2024"
 
 [dependencies]

Cargo.toml

@@ -48,10 +48,23 @@ chv remove 25.12.5.44
 chv init
 ```
 
-This creates a `.clickhouse/` directory in the current folder to contain all ClickHouse data, logs, and temporary files. A `.gitignore` is included so it won't be committed.
+This creates a `.clickhouse/` directory in the current folder with a `.gitignore` so it won't be committed.
 
 `chv run server` automatically runs `init` if needed, so you can skip this step.
 
+Data is scoped by version — each ClickHouse version gets its own subdirectory under `.clickhouse/`, so switching versions with `chv use` won't cause compatibility issues:
+
+```
+.clickhouse/
+├── .gitignore
+├── 25.12.5.44/
+│   ├── data/
+│   └── ...
+└── 26.1.2.11/
+    ├── data/
+    └── ...
+```
+
 ### Running ClickHouse
 
 ```bash

README.md

@@ -26,10 +26,16 @@ pub fn init() -> Result<()> {
     Ok(())
 }
 
-pub fn ensure_initialized() -> Result<()> {
+pub fn version_data_dir(version: &str) -> PathBuf {
+    local_dir().join(version)
+}
+
+pub fn ensure_initialized(version: &str) -> Result<()> {
     if !is_initialized() {
         init()?;
     }
+    let vdir = version_data_dir(version);
+    std::fs::create_dir_all(&vdir)?;
     Ok(())
 }
 

src/init.rs

@@ -166,8 +166,8 @@ fn run_clickhouse(args: RunArgs) -> Result<()> {
             cmd.arg("server");
             cmd.args(&args);
             if !has_config {
-                init::ensure_initialized()?;
-                cmd.current_dir(init::local_dir());
+                init::ensure_initialized(&version)?;
+                cmd.current_dir(init::version_data_dir(&version));
                 cmd.args(init::server_flags());
             }
             let err = cmd.exec();