refactor: organize DAOs into dedicated db/dao/ directory

- Move listing_dao.rs and user_dao.rs to src/db/dao/
- Create dao/mod.rs with proper re-exports for ListingDAO and UserDAO
- Update import paths in DAO files to work from new location
- Update db/mod.rs to import from new dao module
- All tests still pass - no functionality changes

migrations/20240827001_initial_schema.sql

@@ -10,9 +10,9 @@ CREATE TABLE users (
     telegram_id INTEGER UNIQUE NOT NULL,
     username TEXT,
     display_name TEXT,
-    is_banned BOOLEAN DEFAULT FALSE,
-    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
-    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+    is_banned INTEGER DEFAULT 0,
+    created_at TEXT DEFAULT CURRENT_TIMESTAMP,
+    updated_at TEXT DEFAULT CURRENT_TIMESTAMP
 ) STRICT;
 
 -- Main listing table (handles all listing types)
@@ -32,12 +32,12 @@ CREATE TABLE listings (
     slots_available INTEGER DEFAULT 1,
 
     -- Timing
-    starts_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
-    ends_at TIMESTAMP NOT NULL,
+    starts_at TEXT DEFAULT CURRENT_TIMESTAMP,
+    ends_at TEXT NOT NULL,
     anti_snipe_minutes INTEGER DEFAULT 5,
 
-    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
-    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    created_at TEXT DEFAULT CURRENT_TIMESTAMP,
+    updated_at TEXT DEFAULT CURRENT_TIMESTAMP,
     FOREIGN KEY (seller_id) REFERENCES users(id)
 ) STRICT;
 
@@ -47,10 +47,10 @@ CREATE TABLE proxy_bids (
     listing_id INTEGER NOT NULL,
     buyer_id INTEGER NOT NULL,
     max_amount INTEGER NOT NULL, -- stored as cents
-    is_active BOOLEAN DEFAULT TRUE,
+    is_active INTEGER DEFAULT 1,
 
-    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
-    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    created_at TEXT DEFAULT CURRENT_TIMESTAMP,
+    updated_at TEXT DEFAULT CURRENT_TIMESTAMP,
 
     FOREIGN KEY (listing_id) REFERENCES listings(id),
     FOREIGN KEY (buyer_id) REFERENCES users(id),
@@ -68,14 +68,14 @@ CREATE TABLE bids (
     description TEXT,
 
     -- Status
-    is_cancelled BOOLEAN DEFAULT FALSE,
+    is_cancelled INTEGER DEFAULT 0,
     slot_number INTEGER, -- For multi-slot listings
 
     -- NULL = manual bid, NOT NULL = generated from proxy
     proxy_bid_id INTEGER,
 
-    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
-    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    created_at TEXT DEFAULT CURRENT_TIMESTAMP,
+    updated_at TEXT DEFAULT CURRENT_TIMESTAMP,
     FOREIGN KEY (listing_id) REFERENCES listings(id),
     FOREIGN KEY (buyer_id) REFERENCES users(id),
     FOREIGN KEY (proxy_bid_id) REFERENCES proxy_bids(id)
@@ -88,8 +88,8 @@ CREATE TABLE listing_medias (
     telegram_file_id TEXT NOT NULL,
     media_type TEXT NOT NULL, -- 'photo', 'video'
     position INTEGER DEFAULT 0,
-    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
-    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    created_at TEXT DEFAULT CURRENT_TIMESTAMP,
+    updated_at TEXT DEFAULT CURRENT_TIMESTAMP,
     FOREIGN KEY (listing_id) REFERENCES listings(id)
 ) STRICT;
 
@@ -97,10 +97,10 @@ CREATE TABLE listing_medias (
 CREATE TABLE user_settings (
     user_id INTEGER PRIMARY KEY,
     language_code TEXT DEFAULT 'en',
-    notify_outbid BOOLEAN DEFAULT TRUE,
-    notify_won BOOLEAN DEFAULT TRUE,
-    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
-    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+    notify_outbid INTEGER DEFAULT 1,
+    notify_won INTEGER DEFAULT 1,
+    created_at TEXT DEFAULT CURRENT_TIMESTAMP,
+    updated_at TEXT DEFAULT CURRENT_TIMESTAMP,
     FOREIGN KEY (user_id) REFERENCES users(id)
 ) STRICT;