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/core/migration/20260228203230_blue_harpoon/migration.sql

@@ -0,0 +1,17 @@
+CREATE TABLE `account` (
+	`id` text PRIMARY KEY,
+	`email` text NOT NULL,
+	`url` text NOT NULL,
+	`access_token` text NOT NULL,
+	`refresh_token` text NOT NULL,
+	`token_expiry` integer,
+	`selected_org_id` text,
+	`time_created` integer NOT NULL,
+	`time_updated` integer NOT NULL
+);
+--> statement-breakpoint
+CREATE TABLE `account_state` (
+	`id` integer PRIMARY KEY NOT NULL,
+	`active_account_id` text,
+	FOREIGN KEY (`active_account_id`) REFERENCES `account`(`id`) ON UPDATE no action ON DELETE set null
+);