fix(persistence): migrate all pkg/persistence imports to plugins/infra/database and plugins/infra/cache

- Replace db.DB(ctx) with database.DB(ctx) from plugins/infra/database
- Replace db.Redis/db.PrefixedKey/db.GetJSON/db.SetJSON with cachepkg.* from plugins/infra/cache
- Replace pkg/persistence/idgen with pkg/idgen (already exists)
- Replace pkg/persistence/batchwriter with pkg/batchwriter (already exists)
- Replace pkg/persistence/migrator with pkg/migrator (already exists)
- Replace pkg/persistence/logstore with plugins/domain/risk_control/logstore
- Delete defunct pkg/{persistence,cap,message_gateway,push,shared,task}
- Fix vet issues: db alias in domain_test.go, driver_asynq_worker.TaskHandler reference
- Update Makefile architecture guard
- Update docs and skill references
- Update go.mod: gorilla/sessions promotion to direct dependency

pkg/migrator/goose/sqlite/202608160003_create_message_gateway.sql

@@ -0,0 +1,40 @@
+-- +goose Up
+CREATE TABLE IF NOT EXISTS w_message_channels (
+    id INTEGER PRIMARY KEY,
+    name TEXT NOT NULL,
+    type TEXT NOT NULL,
+    owner_scope TEXT NOT NULL DEFAULT 'system',
+    owner_id INTEGER NULL,
+    enabled INTEGER NOT NULL DEFAULT 1,
+    credentials TEXT NOT NULL DEFAULT '',
+    extra TEXT NOT NULL DEFAULT '',
+    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+CREATE INDEX IF NOT EXISTS idx_w_message_channels_type ON w_message_channels (type);
+
+CREATE TABLE IF NOT EXISTS w_message_bindings (
+    id INTEGER PRIMARY KEY,
+    user_id INTEGER NOT NULL,
+    channel_id INTEGER NOT NULL,
+    platform_user_id TEXT NOT NULL,
+    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+CREATE UNIQUE INDEX IF NOT EXISTS uniq_w_message_bindings_channel_platform
+    ON w_message_bindings (channel_id, platform_user_id);
+CREATE INDEX IF NOT EXISTS idx_w_message_bindings_user ON w_message_bindings (user_id);
+
+CREATE TABLE IF NOT EXISTS w_message_pairing_codes (
+    code TEXT PRIMARY KEY,
+    channel_id INTEGER NOT NULL,
+    platform_user_id TEXT NOT NULL,
+    expires_at DATETIME NOT NULL,
+    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+CREATE INDEX IF NOT EXISTS idx_w_message_pairing_lookup
+    ON w_message_pairing_codes (channel_id, platform_user_id);
+
+-- +goose Down
+DROP TABLE IF EXISTS w_message_pairing_codes;
+DROP TABLE IF EXISTS w_message_bindings;
+DROP TABLE IF EXISTS w_message_channels;