feat(aircoding): AirCoding V2 baseline — deterministic multi-agent architecture

Forked from OpenCode v1.17.4 with multi-agent system:
- 5 agents: aircoding, scheduler, worker, architect, reviewer
- Deterministic DAG scheduling engine (coordinator_tick)
- Tool whitelists as hard enforcement
- AirCoding validation plugin
- V1 requirements: C4 docs, ADR, AGENTS.md, debug-log.md
- Design documents in docs/

packages/ui/src/components/avatar.css

@@ -0,0 +1,49 @@
+[data-component="avatar"] {
+  --avatar-bg: var(--color-surface-info-base);
+  --avatar-fg: var(--color-text-base);
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  flex-shrink: 0;
+  border-radius: var(--radius-sm);
+  border: 1px solid var(--color-border-weak-base);
+  font-family: var(--font-mono);
+  font-weight: 500;
+  text-transform: uppercase;
+  background-color: var(--avatar-bg);
+  color: var(--avatar-fg);
+}
+
+[data-component="avatar"][data-has-image] {
+  background-color: transparent;
+  border: none;
+}
+
+[data-component="avatar"][data-size="small"] {
+  width: 1.25rem;
+  height: 1.25rem;
+  font-size: 0.75rem;
+  line-height: 1;
+}
+
+[data-component="avatar"][data-size="normal"] {
+  width: 1.5rem;
+  height: 1.5rem;
+  font-size: 1.125rem;
+  line-height: 1.5rem;
+}
+
+[data-component="avatar"][data-size="large"] {
+  width: 2rem;
+  height: 2rem;
+  font-size: 1.25rem;
+  line-height: 2rem;
+}
+
+[data-component="avatar"] [data-slot="avatar-image"] {
+  width: 100%;
+  height: 100%;
+  display: block;
+  object-fit: cover;
+  border-radius: inherit;
+}