fix: terminal rendering and dashboard issues

- Fix escape sequence display: filter DA1 responses that can be split across socket reads
- Fix font rendering: use ghostty-web renderer API (setFontFamily/remeasureFont)
- Fix sparklines: update slug-to-service mapping when containers are added/removed
- Improve typeahead thumbnails: increase to 96x72px (4:3 ratio)

src/webterm/docker_exec_session.py

@@ -6,6 +6,7 @@ import asyncio
 import contextlib
 import json
 import logging
+import re
 import socket
 from collections import deque
 from dataclasses import dataclass
@@ -27,6 +28,10 @@ REPLAY_BUFFER_SIZE = 256 * 1024  # 256KB
 DEFAULT_SCREEN_WIDTH = 132
 DEFAULT_SCREEN_HEIGHT = 45
 
+# Pattern to filter out terminal device attribute responses that cause display issues
+# These are responses to queries that shouldn't be displayed as text
+DA_RESPONSE_PATTERN = re.compile(rb'\x1b\[\?[\d;]+c')
+
 
 @dataclass(frozen=True)
 class DockerExecSpec:
@@ -173,8 +178,8 @@ class DockerExecSession(Session):
             sock.close()
             detail = body.decode("utf-8", errors="replace")
             raise RuntimeError(f"Docker API exec start failed ({status}): {detail}")
-        if body:
-            self._pending_output += body
+        # Don't save body from HTTP upgrade - it contains protocol handshake data,
+        # not real terminal output (e.g., device attribute responses like "\x1b[?1;10;0c")
         sock.settimeout(None)
         return sock
 
@@ -297,6 +302,11 @@ class DockerExecSession(Session):
                 data = await queue.get()
                 if not data:
                     break
+                # Filter out device attribute responses that can cause display issues
+                # when split across socket reads
+                data = DA_RESPONSE_PATTERN.sub(b'', data)
+                if not data:
+                    continue
                 await self._add_to_replay_buffer(data)
                 await self._update_screen(data)
                 if self._connector:

src/webterm/local_server.py

@@ -360,12 +360,19 @@ class LocalServer:
     def _on_docker_container_added(self, slug: str, name: str, command: str) -> None:
         """Callback when a Docker container is added."""
         log.info("Container added to dashboard: %s -> %s", name, slug)
+        # Update slug-to-service mapping for sparklines
+        if self._docker_stats:
+            self._slug_to_service[slug] = name
+            log.debug("Added sparkline mapping: %s -> %s", slug, name)
         # Notify SSE subscribers about dashboard change
         self._notify_activity("__dashboard__")
 
     def _on_docker_container_removed(self, slug: str) -> None:
         """Callback when a Docker container is removed."""
         log.info("Container removed from dashboard: %s", slug)
+        # Remove slug-to-service mapping
+        if self._docker_stats and slug in self._slug_to_service:
+            del self._slug_to_service[slug]
         # Invalidate any cached screenshots
         self._screenshot_cache.pop(slug, None)
         self._screenshot_cache_etag.pop(slug, None)
@@ -769,7 +776,7 @@ class LocalServer:
         .floating-results .search-query {{ font-size: 18px; font-weight: bold; color: #3b82f6; }}
         .floating-results .result-item {{ display: flex; align-items: center; gap: 12px; padding: 12px; margin: 6px 0; border: 1px solid #334155; border-radius: 6px; cursor: pointer; transition: all 0.15s; }}
         .floating-results .result-item:hover, .floating-results .result-item.active {{ background: #334155; border-color: #3b82f6; }}
-        .floating-results .result-thumb {{ width: 72px; height: 40px; flex: 0 0 auto; border-radius: 4px; border: 1px solid #334155; background: #0b1220; object-fit: contain; }}
+        .floating-results .result-thumb {{ width: 96px; height: 72px; flex: 0 0 auto; border-radius: 4px; border: 1px solid #334155; background: #0b1220; object-fit: contain; }}
         .floating-results .result-content {{ display: flex; flex-direction: column; gap: 2px; }}
         .floating-results .result-title {{ font-weight: bold; margin-bottom: 4px; }}
         .floating-results .result-meta {{ font-size: 12px; color: #94a3b8; }}

src/webterm/static/js/terminal.ts

@@ -515,9 +515,12 @@ class WebTerminal {
     // Wait for fonts to load before fitting to ensure correct measurements
     this.waitForFonts().then(() => {
       console.log("[webterm:init] Fonts loaded, reapplying font family and fitting...");
-      this.terminal.options.fontFamily = this.fontFamily;
-      if (typeof (this.terminal as unknown as { loadFonts?: () => void }).loadFonts === "function") {
-        (this.terminal as unknown as { loadFonts: () => void }).loadFonts();
+      // Use renderer's setFontFamily method to properly update fonts
+      const renderer = (this.terminal as unknown as { renderer?: { setFontFamily: (family: string) => void; remeasureFont: () => void } }).renderer;
+      if (renderer) {
+        renderer.setFontFamily(this.fontFamily);
+        renderer.remeasureFont();
+        console.log("[webterm:init] Font family updated via renderer");
       }
       this.fit();
       console.log("[webterm:init] fit() completed");