v0.9.0: Generic payload support via PayloadCollector (#10)

* Add generic payload support with PayloadCollector trait

Introduces a generic type parameter P to CommandContext, allowing users
to pass custom typed data from client to daemon handler. Payload is
auto-collected via PayloadCollector::collect() before each command.

- Add PayloadCollector trait with async fn collect() -> Self
- Make CommandContext<P>, SocketMessage<P>, CommandHandler<P> generic
- Make DaemonServer<H, P> and DaemonClient<P> generic
- Default P = () maintains full backward compatibility
- Add to prelude: PayloadCollector, Serialize, Deserialize

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Add tests for generic payload feature

- Add 7 unit tests for PayloadCollector and CommandContext<P> serialization
- Add 2 integration tests for end-to-end payload flow through sockets
- Total test count: 73 (was 64)

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Remove prd

* Remove EnvVarFilter in favor of PayloadCollector

Users who need env vars should include them directly in their payload
struct via PayloadCollector::collect(). This simplifies the API by
unifying two mechanisms into one.

Removed:
- EnvVarFilter struct and methods
- env_vars field from CommandContext
- with_env_filter() from DaemonClient
- 5 EnvVarFilter unit tests

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Bump to v0.9.0, update CHANGELOG for EnvVarFilter removal

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Update docs for v0.9.0: payload, handler signature, Windows support

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Fix clippy warning: use match instead of is_err + unwrap

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* Fix CHANGELOG migration example: remove incorrect turbofish

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: akesson

.claude/CLAUDE.md

@@ -4,7 +4,7 @@ This file provides guidance to Claude Code (claude.ai/code) when working with co
 
 ## Project Overview
 
-`daemon-cli` is a Rust library for building streaming daemon-client applications with automatic lifecycle management. It enables CLI tools to communicate with long-running background processes via stdin/stdout streaming over Unix domain sockets.
+`daemon-cli` is a Rust library for building streaming daemon-client applications with automatic lifecycle management. It enables CLI tools to communicate with long-running background processes via stdin/stdout streaming (Unix domain sockets on Unix, named pipes on Windows).
 
 ## Essential Commands
 
@@ -91,16 +91,22 @@ Note: Multiple clients can execute commands concurrently. Each connection gets i
 The `CommandHandler` trait is the primary extension point:
 ```rust
 #[async_trait]
-pub trait CommandHandler: Send + Sync {
+pub trait CommandHandler<P = ()>: Send + Sync
+where
+    P: PayloadCollector,
+{
     async fn handle(
         &self,
-        command: &str,           // Command string from stdin
-        output: impl AsyncWrite,  // Stream output here incrementally
+        command: &str,              // Command string from stdin
+        ctx: CommandContext<P>,     // Terminal info + custom payload
+        output: impl AsyncWrite,    // Stream output here incrementally
         cancel_token: CancellationToken,  // Check for cancellation
-    ) -> Result<()>;
+    ) -> Result<i32>;  // Return exit code (0 = success)
 }
 ```
 
+The generic `P` parameter allows passing custom data from client to daemon via `PayloadCollector::collect()`.
+
 **Concurrency Considerations:**
 - Handlers must implement `Clone + Send + Sync` for concurrent execution
 - Each client connection receives a cloned handler instance
@@ -126,7 +132,7 @@ use daemon_cli::prelude::*;
 
 let handler = MyHandler::new();
 // Automatically detects daemon name and binary mtime
-let (server, _handle) = DaemonServer::new("/path/to/project", handler);
+let (server, _handle) = DaemonServer::new("/path/to/project", handler, StartupReason::default());
 // Default: max 100 concurrent connections
 ```
 
@@ -139,6 +145,7 @@ let handler = MyHandler::new();
 let (server, _handle) = DaemonServer::new_with_limit(
     "/path/to/project",
     handler,
+    StartupReason::default(),
     10  // Max 10 concurrent clients
 );
 ```
@@ -147,8 +154,8 @@ When the limit is reached, new connections wait for an available slot. This is i
 
 ## Platform Requirements
 
-- Unix-like systems only (Linux, macOS)
-- Uses Unix domain sockets (not portable to Windows)
+- Cross-platform: Linux, macOS, Windows
+- Uses Unix domain sockets on Unix, named pipes on Windows
 - Edition: Rust 2024
 
 # Other memory

.gitignore

@@ -4,5 +4,4 @@ Cargo.lock
 
 /*.md
 !/README.md
-!/PRD.md
 !/CHANGELOG.md

CHANGELOG.md

@@ -5,6 +5,36 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.9.0] - 2025-12-29
+
+### Changed (BREAKING)
+
+- Removed `EnvVarFilter` - use `PayloadCollector` trait instead for passing env vars
+- `CommandContext<P>` is now generic with custom payload support via `PayloadCollector`
+- Removed `DaemonClient::with_env_filter()` method
+
+### Migration
+
+```rust
+// Before (0.8.0):
+let client = DaemonClient::connect(path)
+    .await?
+    .with_env_filter(EnvVarFilter::with_names(["MY_VAR"]));
+
+// After (0.9.0):
+#[derive(Serialize, Deserialize, Clone, Default)]
+struct MyPayload { my_var: Option<String> }
+
+#[async_trait]
+impl PayloadCollector for MyPayload {
+    async fn collect() -> Self {
+        Self { my_var: std::env::var("MY_VAR").ok() }
+    }
+}
+
+let client = DaemonClient::<MyPayload>::connect(path).await?;
+```
+
 ## [0.8.0] - 2025-12-09
 
 ### Changed (BREAKING)

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "daemon-cli"
-version = "0.8.0"
+version = "0.9.0"
 edition = "2024"
 
 [dependencies]