initial agent-mgr: app builder platform MVP

Go API server + Preact UI + Claude Code adapter.
- App-centric model (ideas, not repos)
- AgentProvider interface for multi-agent support
- K8s pod lifecycle for sandboxed agent sessions
- Gitea integration (create repos, push branches)
- WebSocket streaming for live session output
- Woodpecker CI/CD pipelines (kaniko build + kubectl deploy)

internal/store/migrations/001_init.sql

@@ -0,0 +1,29 @@
+CREATE TABLE IF NOT EXISTS apps (
+    id          UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    name        TEXT NOT NULL,
+    description TEXT NOT NULL DEFAULT '',
+    status      TEXT NOT NULL DEFAULT 'draft',
+    repo_owner  TEXT NOT NULL DEFAULT '',
+    repo_name   TEXT NOT NULL DEFAULT '',
+    preview_url TEXT NOT NULL DEFAULT '',
+    created_at  TIMESTAMPTZ NOT NULL DEFAULT now(),
+    updated_at  TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+CREATE TABLE IF NOT EXISTS sessions (
+    id         UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    app_id     UUID NOT NULL REFERENCES apps(id) ON DELETE CASCADE,
+    provider   TEXT NOT NULL DEFAULT 'claude-code',
+    status     TEXT NOT NULL DEFAULT 'pending',
+    prompt     TEXT NOT NULL DEFAULT '',
+    branch     TEXT NOT NULL DEFAULT '',
+    pod_name   TEXT NOT NULL DEFAULT '',
+    config     JSONB NOT NULL DEFAULT '{}',
+    cost_json  JSONB NOT NULL DEFAULT '{}',
+    created_at TIMESTAMPTZ NOT NULL DEFAULT now(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT now()
+);
+
+CREATE INDEX idx_sessions_app_id ON sessions(app_id);
+CREATE INDEX idx_sessions_status ON sessions(status);
+CREATE INDEX idx_apps_status ON apps(status);