feat: add initial socket api for workspace and pane control

add unix socket request/response api scaffolding

implement initial workspace and pane commands:
- ping
- workspace.list
- workspace.get
- workspace.create
- pane.list
- pane.get
- pane.read
- pane.send_text
- pane.send_keys
- pane.wait_for_output

improve pane read semantics:
- visible trims trailing blank viewport rows
- recent reads from parser scrollback/current screen
- wait_for_output returns matched snapshot plus matched_line

add real subprocess integration tests for socket api

1 files changed, 1 insertions, 0 deletions

diff --git a/Cargo.toml b/Cargo.toml
index 3119832f..a73f53b1 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -16,6 +16,7 @@ bytes = "1"
 crossterm = "0.29"
 portable-pty = "0.9"
 ratatui = "0.30"
+regex = "1"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 tokio = { version = "1", features = ["rt-multi-thread", "macros", "sync", "time"] }