feat: extract TUI layer into standalone clemitui crate (#101)

* feat: extract TUI layer into standalone clemitui crate (#100)

Extract formatting, logging, and text buffering into a reusable
clemitui crate that can be used by any ACP-compatible AI agent.

Changes:
- Create crates/clemitui/ with format.rs, logging.rs, text_buffer.rs
- Refactor clemini to re-export from clemitui, keeping genai-rs wrappers
- Update CLAUDE.md with workspace structure documentation
- Fix -p mode hang by explicitly dropping events_guard before await

The new crate takes primitive types (strings, durations, token counts)
instead of genai-rs types, enabling reuse without model-specific deps.

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

* fix: disambiguate doc link for format module

Use `mod@format` to distinguish from the built-in `format!` macro.

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

* chore: address review feedback

- Remove unused agent-client-protocol dependency from clemitui
- Update issue #100 to track extraction phases

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

* chore(clemitui): remove unused tokio and tracing dependencies

These dependencies were never used in clemitui:
- tokio: logging.rs uses std::sync::RwLock, not tokio::sync
- tracing: no warn!/info!/debug! macros used anywhere

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

* fix(clemitui): address audit findings

API improvements:
- Make SKIN and render_markdown_nowrap pub(crate) - internal only
- Check LOGGING_DISABLED flag in log_event()/log_event_line()
- Add enable_logging() for test state reset

Test improvements:
- Add boundary tests for string truncation (79/80/81 chars)
- Add edge cases for estimate_tokens (null, empty, large)
- Strengthen render_markdown_nowrap test (verify ANSI codes)
- Add plain text and header tests for markdown rendering

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

* fix(tests): make test_edit_error_recovery deterministic

The test was flaky because:
1. Model behavior varied (different case handling approaches)
2. Validator interpretation of "appropriate" was subjective

Fix:
- Add deterministic check: verify file contains "Goodbye" (edit happened)
- Use lenient semantic check: "Did model attempt the edit?" (not "was
  case handling appropriate?")

This separates "did it work" (deterministic) from "did it communicate"
(lenient), eliminating the subjective judgment that caused flakiness.

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

* docs: remove outdated clemitui dependency comment

The comment referenced agent-client-protocol which was removed.
The Design note below already explains the genai-rs separation.

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

---------

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

Author: evansenter

CLAUDE.md

@@ -33,7 +33,19 @@ Logs are stored in `~/.clemini/logs/` with daily rotation.
 
 The CLI has three modes: single-prompt (`-p "prompt"`), interactive REPL, and MCP server (`--mcp-server`).
 
-### Module Structure
+### Workspace Structure
+
+This project is a Cargo workspace with two crates:
+
+```
+.
+├── Cargo.toml       # Workspace root
+├── src/             # clemini crate (AI agent)
+└── crates/
+    └── clemitui/    # TUI library crate (reusable by any ACP agent)
+```
+
+#### clemini (AI Agent)
 
 ```
 src/
@@ -45,14 +57,34 @@ src/
 ├── diff.rs          # Diff formatting for edit tool output
 ├── event_bus.rs     # Cross-session event bus (SQLite-backed)
 ├── events.rs        # EventHandler trait, TerminalEventHandler
-├── format.rs        # Pure formatting functions, TextBuffer, markdown rendering
-├── logging.rs       # OutputSink trait, log_event functions
+├── format.rs        # Re-exports clemitui + genai-rs-specific formatters
+├── logging.rs       # Re-exports clemitui::logging
 ├── mcp.rs           # MCP server implementation
 ├── plan.rs          # Plan mode manager
 ├── system_prompt.md # System prompt for Gemini (included at compile time)
-└── tools/           # Tool implementations (bash, read_file, etc.)
+└── tools/           # Tool implementations
+    ├── mod.rs       # CleminiToolService, ToolEmitter trait, EventsGuard
+    ├── tasks.rs     # Unified task registry (Task enum, namespaced IDs)
+    ├── bash/        # BashTool (mod.rs) + safety patterns (safety.rs)
+    └── ...          # Individual tool modules (edit, read, grep, etc.)
 ```
 
+#### clemitui (TUI Library)
+
+Standalone crate for terminal UI, usable by any ACP-compatible agent:
+
+```
+crates/clemitui/
+├── Cargo.toml
+└── src/
+    ├── lib.rs       # Re-exports
+    ├── format.rs    # Primitive formatting functions (tool output, warnings)
+    ├── logging.rs   # OutputSink trait, log_event functions
+    └── text_buffer.rs # TextBuffer for streaming markdown
+```
+
+**Design**: clemitui takes primitive types (strings, durations, token counts), not genai-rs types. This allows it to work with any ACP agent. clemini's format.rs re-exports these and adds genai-rs-specific wrappers.
+
 ### Event-Driven Architecture
 
 The agent (`src/agent.rs`) is decoupled from UI via channel-based events:
@@ -162,6 +194,8 @@ If you're unsure whether coverage is sufficient, add more tests. Undertesting ca
 - `confirmation_tests.rs` - Confirmation flow for destructive commands
 - `tool_output_tests.rs` - Tool output events and model interpretation
 - `semantic_integration_tests.rs` - Multi-turn state, error recovery, code analysis
+- `acp_integration_tests.rs` - ACP subagent spawning and communication
+- `background_tasks_tests.rs` - Background task execution and output retrieval
 - `event_ordering_tests.rs` - Tool output event ordering (no API key required)
 
 Run locally with: `cargo test --test <name> -- --include-ignored --nocapture`

Cargo.toml

@@ -1,3 +1,7 @@
+[workspace]
+members = [".", "crates/clemitui"]
+resolver = "3"
+
 [package]
 name = "clemini"
 version = "0.2.0"
@@ -7,6 +11,8 @@ description = "A Gemini-powered coding CLI, built with genai-rs"
 license = "MIT"
 
 [dependencies]
+# Internal crates
+clemitui = { path = "crates/clemitui" }
 # AI
 genai-rs = "0.7.2"
 

crates/clemitui/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "clemitui"
+version = "0.1.0"
+edition = "2024"
+rust-version = "1.88"
+description = "Terminal UI for ACP-compatible AI agents"
+license = "MIT"
+repository = "https://github.com/evansenter/clemini"
+keywords = ["cli", "tui", "ai", "llm", "acp"]
+categories = ["command-line-interface", "text-processing"]
+
+[dependencies]
+# Terminal formatting
+colored = "2"
+termimad = "0.30"
+
+# Serialization (for tool args formatting)
+serde_json = "1"
+
+[dev-dependencies]
+tempfile = "3.10"