feat: full TUI viewer — scroll, refresh, task lookup without leaving

Replaced curses/less pager with raw terminal TUI:
- Alternate screen buffer with full ANSI color support
- Arrow keys / j/k / PgUp/PgDn / mouse scroll to navigate
- r = refresh in-place (re-fetches, resets to top)
- : = type a task number to view details inline
- b = back to briefing from task view
- q = quit
- Space = page down
- Status bar with scroll percentage

No need to exit and re-enter — everything happens in one view.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

briefing

@@ -7,7 +7,7 @@ Usage: briefing [7|30] [client]
   briefing 7 OHS  — 7-day, OHS only
 """
 
-import json, sys, subprocess, re, readline, os, io
+import json, sys, subprocess, re, os, io, tty, termios, struct, fcntl, signal
 from contextlib import redirect_stdout
 from datetime import datetime, timezone, timedelta
 
@@ -450,18 +450,8 @@ def show_task_detail(nid):
     print(f"\n  {DIM}URL: https://teacup.nodie.co.za/?sn={node.get('nodesid')}{RESET}")
 
 
-def show_in_pager(content):
-    """Show content in less, starting at the top. User scrolls down, q to exit."""
-    try:
-        proc = subprocess.Popen(['less', '-R', '-S', '--mouse'], stdin=subprocess.PIPE)
-        proc.communicate(input=content.encode())
-    except (BrokenPipeError, FileNotFoundError):
-        # Fallback: just print if less isn't available
-        print(content)
-
-
-def fetch_and_render(range_days, client):
-    """Fetch briefing data from API, render to pager. Returns tasks list."""
+def fetch_briefing_content(range_days, client):
+    """Fetch briefing data from API and render to string. Returns (content, tasks)."""
     url = f"{BASE_URL}/briefing?range={range_days}"
     if client:
         url += f"&client={client}"
@@ -472,23 +462,18 @@ def fetch_and_render(range_days, client):
     )
 
     if not result.stdout.strip():
-        print(f"{RED}Empty response from API{RESET}")
-        return []
+        return f"{RED}Empty response from API{RESET}\n", []
 
     try:
         data = json.loads(result.stdout)
     except json.JSONDecodeError:
-        print(f"{RED}Invalid JSON response{RESET}")
-        print(result.stdout[:500])
-        return []
+        return f"{RED}Invalid JSON response{RESET}\n", []
 
     if not data.get("success"):
-        print(f"{RED}API error: {data.get('message', 'Unknown')}{RESET}")
-        return []
+        return f"{RED}API error: {data.get('message', 'Unknown')}{RESET}\n", []
 
     raw = data["data"]
 
-    # Render to buffer
     buf = io.StringIO()
     with redirect_stdout(buf):
         render_summary(raw.get('summary', {}), int(range_days))
@@ -496,47 +481,201 @@ def fetch_and_render(range_days, client):
         render_tasks(raw.get('tasks', []))
         render_commits(raw.get('git_commits', {}))
 
-    # Show in pager (starts at top, scroll down for more)
-    if sys.stdout.isatty():
-        show_in_pager(buf.getvalue())
+    return buf.getvalue(), raw.get('tasks', [])
+
+
+def fetch_task_content(nid):
+    """Fetch task detail and render to string."""
+    buf = io.StringIO()
+    with redirect_stdout(buf):
+        show_task_detail(nid)
+    return buf.getvalue()
+
+
+# ── Terminal helpers ────────────────────────────────────────────────
+
+def get_terminal_size():
+    try:
+        result = struct.unpack('hh', fcntl.ioctl(sys.stdout, termios.TIOCGWINSZ, b'\0' * 4))
+        return result[0], result[1]  # rows, cols
+    except Exception:
+        return 40, 80
+
+
+def read_key(fd):
+    """Read a keypress from raw terminal. Returns key string."""
+    ch = os.read(fd, 1)
+    if not ch:
+        return ''
+    if ch == b'\x1b':
+        # Escape sequence
+        seq = os.read(fd, 2)
+        if seq == b'[A': return 'UP'
+        if seq == b'[B': return 'DOWN'
+        if seq == b'[5': os.read(fd, 1); return 'PGUP'
+        if seq == b'[6': os.read(fd, 1); return 'PGDN'
+        if seq == b'[H': return 'HOME'
+        if seq == b'[F': return 'END'
+        if seq == b'[M':
+            # Mouse event: read 3 more bytes
+            mouse = os.read(fd, 3)
+            btn = mouse[0] - 32
+            if btn == 64: return 'SCROLLUP'
+            if btn == 65: return 'SCROLLDN'
+            return ''
+        return 'ESC'
+    return ch.decode('utf-8', errors='replace')
+
+
+def tui_viewer(range_days, client):
+    """Raw-terminal scrollable viewer with ANSI color support."""
+    fd = sys.stdin.fileno()
+    old_settings = termios.tcgetattr(fd)
+
+    # Switch to alternate screen buffer, hide cursor
+    sys.stdout.write('\033[?1049h\033[?25l')
+    # Enable mouse reporting (SGR mode for scroll)
+    sys.stdout.write('\033[?1000h\033[?1006h')
+    sys.stdout.flush()
+
+    scroll = 0
+    lines = []
+    tasks = []
+    briefing_lines = []
+    viewing_task = False
+    input_mode = False
+    input_buf = ""
+    status_msg = ""
+
+    def split_lines(content):
+        return content.split('\n')
+
+    def render():
+        rows, cols = get_terminal_size()
+        view_height = rows - 1  # bottom row = status bar
+
+        # Move cursor to top-left, clear screen
+        out = '\033[H\033[2J'
+
+        for i in range(view_height):
+            line_idx = scroll + i
+            if line_idx < len(lines):
+                line = lines[line_idx]
+                out += f'\033[{i+1};1H{line}\033[K'
             else:
-        print(buf.getvalue())
+                out += f'\033[{i+1};1H\033[K'
 
-    return raw.get('tasks', [])
+        # Status bar (bottom row, reverse video)
+        if input_mode:
+            bar = f" Task #: {input_buf}\u2588"
+        elif status_msg:
+            bar = f" {status_msg}"
+        else:
+            bar = " \u2191\u2193/jk scroll | r refresh | : task# | b back | q quit"
 
+        # Scroll percentage
+        if len(lines) > view_height:
+            pct = min(100, int((scroll + view_height) / max(1, len(lines)) * 100))
+            bar_right = f" {pct}% "
+        else:
+            bar_right = ""
 
-def interactive_mode(tasks, range_days, client):
-    """Interactive prompt — type a task number for details, 'r' to refresh."""
-    print(f"\n{BOLD}{CYAN}{'─' * 60}{RESET}")
-    print(f"{DIM}Commands: task number | r = refresh | q = quit{RESET}")
-    print(f"{BOLD}{CYAN}{'─' * 60}{RESET}")
+        bar_pad = cols - len(bar) - len(bar_right)
+        if bar_pad < 0:
+            bar_pad = 0
+        out += f'\033[{rows};1H\033[7m{bar}{" " * bar_pad}{bar_right}\033[0m'
+
+        sys.stdout.write(out)
+        sys.stdout.flush()
+
+    def load_briefing():
+        nonlocal lines, tasks, scroll, status_msg, briefing_lines
+        status_msg = "Loading..."
+        render()
+        content, tasks = fetch_briefing_content(range_days, client)
+        lines = split_lines(content)
+        briefing_lines = lines[:]
+        scroll = 0
+        status_msg = ""
+
+    def load_task(nid):
+        nonlocal lines, scroll, status_msg
+        status_msg = f"Loading #{nid}..."
+        render()
+        content = fetch_task_content(nid)
+        lines = split_lines(content)
+        scroll = 0
+        status_msg = ""
+
+    try:
+        tty.setraw(fd)
+        load_briefing()
 
         while True:
-        try:
-            inp = input(f"\n{BOLD}{CYAN}#{RESET} ").strip()
-        except (EOFError, KeyboardInterrupt):
-            print()
-            break
+            render()
+            key = read_key(fd)
+            rows, cols = get_terminal_size()
+            view_height = rows - 1
+            max_scroll = max(0, len(lines) - view_height)
 
-        if not inp or inp.lower() in ('q', 'quit', 'exit'):
-            break
-
-        # Refresh
-        if inp.lower() in ('r', 'refresh'):
-            print(f"\n{DIM}Refreshing...{RESET}\n")
-            tasks = fetch_and_render(range_days, client)
-            print(f"\n{BOLD}{CYAN}{'─' * 60}{RESET}")
-            print(f"{DIM}Commands: task number | r = refresh | q = quit{RESET}")
-            print(f"{BOLD}{CYAN}{'─' * 60}{RESET}")
+            if input_mode:
+                if key == 'ESC':
+                    input_mode = False
+                    input_buf = ""
+                elif key in ('\r', '\n'):
+                    input_mode = False
+                    task_num = input_buf.strip().lstrip('#')
+                    input_buf = ""
+                    if task_num.isdigit():
+                        viewing_task = True
+                        load_task(int(task_num))
+                elif key in ('\x7f', '\x08'):  # Backspace
+                    input_buf = input_buf[:-1]
+                elif len(key) == 1 and ord(key) >= 32:
+                    input_buf += key
                 continue
 
-        # Strip # prefix if present
-        inp = inp.lstrip('#')
+            if key == 'q':
+                break
+            elif key == 'r':
+                viewing_task = False
+                load_briefing()
+            elif key == ':':
+                input_mode = True
+                input_buf = ""
+            elif key == 'b':
+                if viewing_task:
+                    viewing_task = False
+                    lines = briefing_lines[:]
+                    scroll = 0
+            elif key in ('UP', 'k'):
+                scroll = max(0, scroll - 1)
+            elif key in ('DOWN', 'j'):
+                scroll = min(max_scroll, scroll + 1)
+            elif key == 'PGUP':
+                scroll = max(0, scroll - view_height)
+            elif key == 'PGDN':
+                scroll = min(max_scroll, scroll + view_height)
+            elif key in ('HOME', 'g'):
+                scroll = 0
+            elif key in ('END', 'G'):
+                scroll = max_scroll
+            elif key == 'SCROLLUP':
+                scroll = max(0, scroll - 3)
+            elif key == 'SCROLLDN':
+                scroll = min(max_scroll, scroll + 3)
+            elif key == ' ':
+                scroll = min(max_scroll, scroll + view_height)
 
-        if inp.isdigit():
-            show_task_detail(int(inp))
-        else:
-            print(f"  {DIM}Commands: task number | r = refresh | q = quit{RESET}")
+    except (KeyboardInterrupt, EOFError):
+        pass
+    finally:
+        # Restore terminal
+        termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
+        sys.stdout.write('\033[?1000l\033[?1006l')  # disable mouse
+        sys.stdout.write('\033[?25h')  # show cursor
+        sys.stdout.write('\033[?1049l')  # restore main screen
+        sys.stdout.flush()
 
 
 def main():
@@ -549,11 +688,12 @@ def main():
     if args:
         client = args[0]
 
-    tasks = fetch_and_render(range_days, client)
-
-    # Interactive mode
-    if sys.stdin.isatty():
-        interactive_mode(tasks, range_days, client)
+    if sys.stdout.isatty():
+        tui_viewer(range_days, client)
+    else:
+        # Non-interactive: just print
+        content, _ = fetch_briefing_content(range_days, client)
+        print(content)
 
 
 if __name__ == "__main__":