fix: index_create updates tracked project for search_text

index_create and index_update now update the MCP server's tracked
project path so subsequent calls like search_text use the same
project. search_text also gains an optional 'project' parameter
to explicitly override the default. Closes #9.

src/mcp/mod.rs

@@ -1,7 +1,7 @@
 //! Minimal MCP server: JSON-RPC over stdio, dispatching to the same ops as the CLI.
 
 use std::io::{BufRead, Write};
-use std::path::Path;
+use std::path::{Path, PathBuf};
 
 use anyhow::Result;
 use serde_json::{Value, json};
@@ -10,6 +10,7 @@ const PROTOCOL_VERSION: &str = "2024-11-05";
 
 pub fn serve(project: &Path) -> Result<()> {
     eprintln!("rustytokens MCP server listening on stdio");
+    let mut project = project.to_path_buf();
     let stdin = std::io::stdin();
     let stdout = std::io::stdout();
     for line in stdin.lock().lines() {
@@ -39,7 +40,7 @@ pub fn serve(project: &Path) -> Result<()> {
                 continue;
             }
         };
-        if let Some(resp) = handle(&msg, project) {
+        if let Some(resp) = handle(&msg, &mut project) {
             let mut out = stdout.lock();
             serde_json::to_writer(&mut out, &resp)?;
             out.write_all(b"\n")?;
@@ -49,7 +50,7 @@ pub fn serve(project: &Path) -> Result<()> {
     Ok(())
 }
 
-fn handle(msg: &Value, project: &Path) -> Option<Value> {
+fn handle(msg: &Value, project: &mut PathBuf) -> Option<Value> {
     let id = msg.get("id").cloned();
 
     // Notifications have no id -> no response.
@@ -101,7 +102,7 @@ fn handle(msg: &Value, project: &Path) -> Option<Value> {
     }
 }
 
-fn call_tool(name: &str, args: &Value, project: &Path) -> Value {
+fn call_tool(name: &str, args: &Value, project: &mut PathBuf) -> Value {
     let result: Result<Value> = dispatch(name, args, project);
     match result {
         Ok(v) => json!({
@@ -114,7 +115,7 @@ fn call_tool(name: &str, args: &Value, project: &Path) -> Value {
     }
 }
 
-fn dispatch(name: &str, args: &Value, project: &Path) -> Result<Value> {
+fn dispatch(name: &str, args: &Value, project: &mut PathBuf) -> Result<Value> {
     use crate::ops;
 
     fn req_str<'a>(args: &'a Value, key: &str, tool: &str) -> Result<&'a str> {
@@ -128,8 +129,16 @@ fn dispatch(name: &str, args: &Value, project: &Path) -> Result<Value> {
     let excludes = crate::config::ExcludeSet::new(&exclude_list(args));
 
     match name {
-        "index_create" => ops::index_create(Path::new(req_str(args, "path", name)?)),
-        "index_update" => ops::index_update(Path::new(req_str(args, "path", name)?)),
+        "index_create" => {
+            let path = PathBuf::from(req_str(args, "path", name)?);
+            project.clone_from(&path);
+            ops::index_create(&path)
+        }
+        "index_update" => {
+            let path = PathBuf::from(req_str(args, "path", name)?);
+            project.clone_from(&path);
+            ops::index_update(&path)
+        }
         "index_file" => ops::index_file(project, req_str(args, "path", name)?),
         "search_symbols" => ops::search_symbols(
             project,
@@ -143,15 +152,20 @@ fn dispatch(name: &str, args: &Value, project: &Path) -> Result<Value> {
                 .unwrap_or(200),
             &excludes,
         ),
-        "search_text" => ops::search_text(
-            project,
-            req_str(args, "query", name)?,
-            args.get("limit")
-                .and_then(|v| v.as_u64())
-                .map(|n| n as usize)
-                .unwrap_or(100),
-            &excludes,
-        ),
+        "search_text" => {
+            let search_project = opt_str("project")
+                .map(PathBuf::from)
+                .unwrap_or_else(|| project.clone());
+            ops::search_text(
+                &search_project,
+                req_str(args, "query", name)?,
+                args.get("limit")
+                    .and_then(|v| v.as_u64())
+                    .map(|n| n as usize)
+                    .unwrap_or(100),
+                &excludes,
+            )
+        }
         "inspect_symbol" => {
             if let Some(id) = args.get("id").and_then(|v| v.as_i64()) {
                 ops::inspect_symbol(project, &id.to_string())
@@ -272,6 +286,7 @@ fn tools() -> Value {
                 "type": "object",
                 "properties": {
                     "query": { "type": "string", "description": "Text or phrase to search for" },
+                    "project": { "type": "string", "description": "Project directory to search (defaults to the last indexed project)" },
                     "limit": { "type": "integer", "description": "Maximum matching files (default 100)" },
                     "exclude": {
                         "type": "array",