fix: migration code not working

- read database config from config file
- rename migration file to expected file name format

apps/backend/internal/database/migrations/001_initial.up.sql

@@ -0,0 +1,94 @@
+-- ============================================================================
+-- Application Tables
+-- ============================================================================
+
+CREATE TABLE IF NOT EXISTS users (
+    id UUID PRIMARY KEY,
+    display_name TEXT,
+    email TEXT NOT NULL UNIQUE,
+    password TEXT NOT NULL,
+    storage_usage_bytes BIGINT NOT NULL,
+    storage_quota_bytes BIGINT NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX idx_users_email ON users(email);
+
+CREATE TABLE IF NOT EXISTS refresh_tokens (
+    id UUID PRIMARY KEY,
+    user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    token_hash TEXT NOT NULL UNIQUE,
+    expires_at TIMESTAMPTZ NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX idx_refresh_tokens_user_id ON refresh_tokens(user_id);
+CREATE INDEX idx_refresh_tokens_token_hash ON refresh_tokens(token_hash);
+CREATE INDEX idx_refresh_tokens_expires_at ON refresh_tokens(expires_at);
+
+-- Virtual filesystem nodes (unified files + directories)
+CREATE TABLE IF NOT EXISTS vfs_nodes (
+    id UUID PRIMARY KEY,
+    public_id TEXT NOT NULL UNIQUE,  -- opaque ID for external API (no timestamp leak)
+    user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    parent_id UUID REFERENCES vfs_nodes(id) ON DELETE CASCADE,  -- NULL = root directory
+    kind TEXT NOT NULL CHECK (kind IN ('file', 'directory')),
+    status TEXT NOT NULL DEFAULT 'ready' CHECK (status IN ('pending', 'ready')),
+    name TEXT NOT NULL,
+    
+    -- File-specific fields (NULL for directories)
+    blob_key TEXT,      -- reference to blob storage (flat mode), NULL for hierarchical
+    size BIGINT,        -- file size in bytes
+    mime_type TEXT,     -- content type
+    
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    deleted_at TIMESTAMPTZ,  -- soft delete for trash
+    
+    -- No duplicate names in same parent (per user, excluding deleted)
+    CONSTRAINT unique_node_name UNIQUE NULLS NOT DISTINCT (user_id, parent_id, name, deleted_at)
+);
+
+CREATE INDEX idx_vfs_nodes_user_id ON vfs_nodes(user_id) WHERE deleted_at IS NULL;
+CREATE INDEX idx_vfs_nodes_parent_id ON vfs_nodes(parent_id) WHERE deleted_at IS NULL;
+CREATE INDEX idx_vfs_nodes_user_parent ON vfs_nodes(user_id, parent_id) WHERE deleted_at IS NULL;
+CREATE INDEX idx_vfs_nodes_kind ON vfs_nodes(user_id, kind) WHERE deleted_at IS NULL;
+CREATE INDEX idx_vfs_nodes_deleted ON vfs_nodes(user_id, deleted_at) WHERE deleted_at IS NOT NULL;
+CREATE INDEX idx_vfs_nodes_public_id ON vfs_nodes(public_id);
+CREATE UNIQUE INDEX idx_vfs_nodes_user_root ON vfs_nodes(user_id) WHERE parent_id IS NULL;  -- one root per user
+CREATE INDEX idx_vfs_nodes_pending ON vfs_nodes(created_at) WHERE status = 'pending';  -- for cleanup job
+
+CREATE TABLE IF NOT EXISTS node_shares (
+    id UUID PRIMARY KEY,
+    node_id UUID NOT NULL REFERENCES vfs_nodes(id) ON DELETE CASCADE,
+    share_token TEXT NOT NULL UNIQUE,
+    expires_at TIMESTAMPTZ,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX idx_node_shares_share_token ON node_shares(share_token);
+CREATE INDEX idx_node_shares_node_id ON node_shares(node_id);
+CREATE INDEX idx_node_shares_expires_at ON node_shares(expires_at) WHERE expires_at IS NOT NULL;
+
+-- ============================================================================
+-- Triggers for updated_at timestamps
+-- ============================================================================
+
+CREATE OR REPLACE FUNCTION update_updated_at_column()
+RETURNS TRIGGER AS $$
+BEGIN
+    NEW.updated_at = NOW();
+    RETURN NEW;
+END;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER update_users_updated_at BEFORE UPDATE ON users
+    FOR EACH ROW EXECUTE FUNCTION update_updated_at_column();
+
+CREATE TRIGGER update_vfs_nodes_updated_at BEFORE UPDATE ON vfs_nodes
+    FOR EACH ROW EXECUTE FUNCTION update_updated_at_column();
+
+CREATE TRIGGER update_node_shares_updated_at BEFORE UPDATE ON node_shares
+    FOR EACH ROW EXECUTE FUNCTION update_updated_at_column();