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
- System prompt injection for routing
- V1 requirements: C4 docs, ADR, AGENTS.md, debug-log.md
- Design documents in docs/

packages/app/src/components/prompt-input/placeholder.ts

@@ -0,0 +1,15 @@
+type PromptPlaceholderInput = {
+  mode: "normal" | "shell"
+  commentCount: number
+  example: string
+  suggest: boolean
+  t: (key: string, params?: Record<string, string>) => string
+}
+
+export function promptPlaceholder(input: PromptPlaceholderInput) {
+  if (input.mode === "shell") return input.t("prompt.placeholder.shell", { example: input.example })
+  if (input.commentCount > 1) return input.t("prompt.placeholder.summarizeComments")
+  if (input.commentCount === 1) return input.t("prompt.placeholder.summarizeComment")
+  if (!input.suggest) return input.t("prompt.placeholder.simple")
+  return input.t("prompt.placeholder.normal", { example: input.example })
+}