Add full-screen TUI with bottom composer

README.md

@@ -35,12 +35,25 @@ Interactive responses stream into the terminal as they are generated, and the
 session keeps conversation history until you reset it. The current session is
 saved to `.harness/session.json` and reloaded the next time the app starts.
 
-For multiline input, end a line with `\` and keep typing:
+The interactive mode is a small full-screen TUI: the transcript scrolls above,
+while the input composer stays pinned to the bottom of the terminal. Press
+`Ctrl+J` to insert a newline while composing.
 
 ```text
-you> summarize this:\
-...> line two\
-...> line three
+┌ transcript
+│ system> Loaded 3 conversation items...
+│ you> ...
+│ assistant> ...
+└────────────────────────────────
+you> input stays here
+```
+
+For multiline input:
+
+```text
+you> summarize this:
+     line two
+     line three
 ```
 
 You can also keep using one-shot mode when scripting:
@@ -175,6 +188,6 @@ npm run dev -- "/greet Ada"
 
 ## Intentional omissions
 
-This first version does **not** include file writes, shell execution, approval
-gates, or persistent sessions. Those are useful, but adding them after the core
-shape is visible keeps the harness easier to reason about.
+This version still does **not** include file writes, shell execution, or approval
+gates. Those are useful, but adding them after the core shape is visible keeps
+the harness easier to reason about.