diff --git a/migrations/postgres/V6__plugin_system.sql b/migrations/postgres/V6__plugin_system.sql
new file mode 100644
index 0000000..bd52a1a
--- /dev/null
+++ b/migrations/postgres/V6__plugin_system.sql
@@ -0,0 +1,15 @@
+-- Plugin registry table
+CREATE TABLE plugin_registry (
+    id TEXT PRIMARY KEY,
+    name TEXT NOT NULL,
+    version TEXT NOT NULL,
+    enabled BOOLEAN NOT NULL DEFAULT TRUE,
+    config_json TEXT,
+    manifest_json TEXT,
+    installed_at TIMESTAMP WITH TIME ZONE NOT NULL,
+    updated_at TIMESTAMP WITH TIME ZONE NOT NULL
+);
+
+-- Index for quick lookups
+CREATE INDEX idx_plugin_registry_enabled ON plugin_registry(enabled);
+CREATE INDEX idx_plugin_registry_name ON plugin_registry(name);
diff --git a/migrations/postgres/V7__user_management.sql b/migrations/postgres/V7__user_management.sql
new file mode 100644
index 0000000..a9eb12f
--- /dev/null
+++ b/migrations/postgres/V7__user_management.sql
@@ -0,0 +1,35 @@
+-- Users table
+CREATE TABLE users (
+    id UUID PRIMARY KEY,
+    username TEXT UNIQUE NOT NULL,
+    password_hash TEXT NOT NULL,
+    role JSONB NOT NULL,
+    created_at TIMESTAMP WITH TIME ZONE NOT NULL,
+    updated_at TIMESTAMP WITH TIME ZONE NOT NULL
+);
+
+-- User profiles table
+CREATE TABLE user_profiles (
+    user_id UUID PRIMARY KEY,
+    avatar_path TEXT,
+    bio TEXT,
+    preferences_json JSONB NOT NULL DEFAULT '{}',
+    created_at TIMESTAMP WITH TIME ZONE NOT NULL,
+    updated_at TIMESTAMP WITH TIME ZONE NOT NULL,
+    FOREIGN KEY (user_id) REFERENCES users(id)
+);
+
+-- User library access table
+CREATE TABLE user_libraries (
+    user_id UUID NOT NULL,
+    root_path TEXT NOT NULL,
+    permission JSONB NOT NULL,
+    granted_at TIMESTAMP WITH TIME ZONE NOT NULL,
+    PRIMARY KEY (user_id, root_path),
+    FOREIGN KEY (user_id) REFERENCES users(id)
+);
+
+-- Indexes for efficient lookups
+CREATE INDEX idx_users_username ON users(username);
+CREATE INDEX idx_user_libraries_user_id ON user_libraries(user_id);
+CREATE INDEX idx_user_libraries_root_path ON user_libraries(root_path);
diff --git a/migrations/postgres/V8__media_server_features.sql b/migrations/postgres/V8__media_server_features.sql
new file mode 100644
index 0000000..7d22838
--- /dev/null
+++ b/migrations/postgres/V8__media_server_features.sql
@@ -0,0 +1,131 @@
+-- Ratings
+CREATE TABLE IF NOT EXISTS ratings (
+    id UUID PRIMARY KEY,
+    user_id UUID NOT NULL,
+    media_id UUID NOT NULL REFERENCES media_items(id) ON DELETE CASCADE,
+    stars INTEGER NOT NULL CHECK (stars >= 1 AND stars <= 5),
+    review_text TEXT,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    UNIQUE(user_id, media_id)
+);
+
+-- Comments
+CREATE TABLE IF NOT EXISTS comments (
+    id UUID PRIMARY KEY,
+    user_id UUID NOT NULL,
+    media_id UUID NOT NULL REFERENCES media_items(id) ON DELETE CASCADE,
+    parent_comment_id UUID REFERENCES comments(id) ON DELETE CASCADE,
+    text TEXT NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+-- Favorites
+CREATE TABLE IF NOT EXISTS favorites (
+    user_id UUID NOT NULL,
+    media_id UUID NOT NULL REFERENCES media_items(id) ON DELETE CASCADE,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    PRIMARY KEY (user_id, media_id)
+);
+
+-- Share links
+CREATE TABLE IF NOT EXISTS share_links (
+    id UUID PRIMARY KEY,
+    media_id UUID NOT NULL REFERENCES media_items(id) ON DELETE CASCADE,
+    created_by UUID NOT NULL,
+    token TEXT NOT NULL UNIQUE,
+    password_hash TEXT,
+    expires_at TIMESTAMPTZ,
+    view_count INTEGER NOT NULL DEFAULT 0,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+-- Playlists
+CREATE TABLE IF NOT EXISTS playlists (
+    id UUID PRIMARY KEY,
+    owner_id UUID NOT NULL,
+    name TEXT NOT NULL,
+    description TEXT,
+    is_public BOOLEAN NOT NULL DEFAULT FALSE,
+    is_smart BOOLEAN NOT NULL DEFAULT FALSE,
+    filter_query TEXT,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+-- Playlist items
+CREATE TABLE IF NOT EXISTS playlist_items (
+    playlist_id UUID NOT NULL REFERENCES playlists(id) ON DELETE CASCADE,
+    media_id UUID NOT NULL REFERENCES media_items(id) ON DELETE CASCADE,
+    position INTEGER NOT NULL DEFAULT 0,
+    added_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    PRIMARY KEY (playlist_id, media_id)
+);
+
+-- Usage events
+CREATE TABLE IF NOT EXISTS usage_events (
+    id UUID PRIMARY KEY,
+    media_id UUID REFERENCES media_items(id) ON DELETE SET NULL,
+    user_id UUID,
+    event_type TEXT NOT NULL,
+    timestamp TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    duration_secs DOUBLE PRECISION,
+    context_json JSONB
+);
+
+CREATE INDEX IF NOT EXISTS idx_usage_events_media ON usage_events(media_id);
+CREATE INDEX IF NOT EXISTS idx_usage_events_user ON usage_events(user_id);
+CREATE INDEX IF NOT EXISTS idx_usage_events_timestamp ON usage_events(timestamp);
+
+-- Watch history / progress
+CREATE TABLE IF NOT EXISTS watch_history (
+    id UUID PRIMARY KEY,
+    user_id UUID NOT NULL,
+    media_id UUID NOT NULL REFERENCES media_items(id) ON DELETE CASCADE,
+    progress_secs DOUBLE PRECISION NOT NULL DEFAULT 0,
+    last_watched TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    UNIQUE(user_id, media_id)
+);
+
+-- Subtitles
+CREATE TABLE IF NOT EXISTS subtitles (
+    id UUID PRIMARY KEY,
+    media_id UUID NOT NULL REFERENCES media_items(id) ON DELETE CASCADE,
+    language TEXT,
+    format TEXT NOT NULL,
+    file_path TEXT,
+    is_embedded BOOLEAN NOT NULL DEFAULT FALSE,
+    track_index INTEGER,
+    offset_ms INTEGER NOT NULL DEFAULT 0,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX IF NOT EXISTS idx_subtitles_media ON subtitles(media_id);
+
+-- External metadata (enrichment)
+CREATE TABLE IF NOT EXISTS external_metadata (
+    id UUID PRIMARY KEY,
+    media_id UUID NOT NULL REFERENCES media_items(id) ON DELETE CASCADE,
+    source TEXT NOT NULL,
+    external_id TEXT,
+    metadata_json JSONB NOT NULL DEFAULT '{}',
+    confidence DOUBLE PRECISION NOT NULL DEFAULT 0.0,
+    last_updated TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX IF NOT EXISTS idx_external_metadata_media ON external_metadata(media_id);
+
+-- Transcode sessions
+CREATE TABLE IF NOT EXISTS transcode_sessions (
+    id UUID PRIMARY KEY,
+    media_id UUID NOT NULL REFERENCES media_items(id) ON DELETE CASCADE,
+    user_id UUID,
+    profile TEXT NOT NULL,
+    cache_path TEXT NOT NULL,
+    status TEXT NOT NULL DEFAULT 'pending',
+    progress DOUBLE PRECISION NOT NULL DEFAULT 0.0,
+    error_message TEXT,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    expires_at TIMESTAMPTZ
+);
+
+CREATE INDEX IF NOT EXISTS idx_transcode_sessions_media ON transcode_sessions(media_id);
diff --git a/migrations/postgres/V9__fix_indexes_and_constraints.sql b/migrations/postgres/V9__fix_indexes_and_constraints.sql
new file mode 100644
index 0000000..a65fda3
--- /dev/null
+++ b/migrations/postgres/V9__fix_indexes_and_constraints.sql
@@ -0,0 +1,26 @@
+-- Drop redundant indexes (already covered by UNIQUE constraints)
+DROP INDEX IF EXISTS idx_users_username;
+DROP INDEX IF EXISTS idx_user_libraries_user_id;
+
+-- Add missing indexes for comments table
+CREATE INDEX IF NOT EXISTS idx_comments_media ON comments(media_id);
+CREATE INDEX IF NOT EXISTS idx_comments_parent ON comments(parent_comment_id);
+
+-- Remove duplicates before adding unique constraint
+DELETE FROM external_metadata e1
+WHERE EXISTS (
+    SELECT 1 FROM external_metadata e2
+    WHERE e1.media_id = e2.media_id
+    AND e1.source = e2.source
+    AND e1.ctid < e2.ctid
+);
+
+-- Add unique constraint for external_metadata (idempotent)
+DO $$
+BEGIN
+    IF NOT EXISTS (
+        SELECT 1 FROM pg_constraint WHERE conname = 'uq_external_metadata_source'
+    ) THEN
+        ALTER TABLE external_metadata ADD CONSTRAINT uq_external_metadata_source UNIQUE(media_id, source);
+    END IF;
+END $$;
diff --git a/migrations/sqlite/V6__plugin_system.sql b/migrations/sqlite/V6__plugin_system.sql
new file mode 100644
index 0000000..f4e7790
--- /dev/null
+++ b/migrations/sqlite/V6__plugin_system.sql
@@ -0,0 +1,15 @@
+-- Plugin registry table
+CREATE TABLE plugin_registry (
+    id TEXT PRIMARY KEY,
+    name TEXT NOT NULL,
+    version TEXT NOT NULL,
+    enabled BOOLEAN NOT NULL DEFAULT TRUE,
+    config_json TEXT,
+    manifest_json TEXT,
+    installed_at TEXT NOT NULL,
+    updated_at TEXT NOT NULL
+);
+
+-- Index for quick lookups
+CREATE INDEX idx_plugin_registry_enabled ON plugin_registry(enabled);
+CREATE INDEX idx_plugin_registry_name ON plugin_registry(name);
diff --git a/migrations/sqlite/V7__user_management.sql b/migrations/sqlite/V7__user_management.sql
new file mode 100644
index 0000000..6584f03
--- /dev/null
+++ b/migrations/sqlite/V7__user_management.sql
@@ -0,0 +1,35 @@
+-- Users table
+CREATE TABLE users (
+    id TEXT PRIMARY KEY,
+    username TEXT UNIQUE NOT NULL,
+    password_hash TEXT NOT NULL,
+    role TEXT NOT NULL,
+    created_at TEXT NOT NULL,
+    updated_at TEXT NOT NULL
+);
+
+-- User profiles table
+CREATE TABLE user_profiles (
+    user_id TEXT PRIMARY KEY,
+    avatar_path TEXT,
+    bio TEXT,
+    preferences_json TEXT NOT NULL DEFAULT '{}',
+    created_at TEXT NOT NULL,
+    updated_at TEXT NOT NULL,
+    FOREIGN KEY (user_id) REFERENCES users(id)
+);
+
+-- User library access table
+CREATE TABLE user_libraries (
+    user_id TEXT NOT NULL,
+    root_path TEXT NOT NULL,
+    permission TEXT NOT NULL,
+    granted_at TEXT NOT NULL,
+    PRIMARY KEY (user_id, root_path),
+    FOREIGN KEY (user_id) REFERENCES users(id)
+);
+
+-- Indexes for efficient lookups
+CREATE INDEX idx_users_username ON users(username);
+CREATE INDEX idx_user_libraries_user_id ON user_libraries(user_id);
+CREATE INDEX idx_user_libraries_root_path ON user_libraries(root_path);
diff --git a/migrations/sqlite/V8__media_server_features.sql b/migrations/sqlite/V8__media_server_features.sql
new file mode 100644
index 0000000..50040c3
--- /dev/null
+++ b/migrations/sqlite/V8__media_server_features.sql
@@ -0,0 +1,143 @@
+-- Ratings
+CREATE TABLE IF NOT EXISTS ratings (
+    id TEXT PRIMARY KEY,
+    user_id TEXT NOT NULL,
+    media_id TEXT NOT NULL,
+    stars INTEGER NOT NULL CHECK (stars >= 1 AND stars <= 5),
+    review_text TEXT,
+    created_at TEXT NOT NULL DEFAULT (datetime('now')),
+    UNIQUE(user_id, media_id),
+    FOREIGN KEY (media_id) REFERENCES media_items(id) ON DELETE CASCADE
+);
+
+-- Comments
+CREATE TABLE IF NOT EXISTS comments (
+    id TEXT PRIMARY KEY,
+    user_id TEXT NOT NULL,
+    media_id TEXT NOT NULL,
+    parent_comment_id TEXT,
+    text TEXT NOT NULL,
+    created_at TEXT NOT NULL DEFAULT (datetime('now')),
+    FOREIGN KEY (media_id) REFERENCES media_items(id) ON DELETE CASCADE,
+    FOREIGN KEY (parent_comment_id) REFERENCES comments(id) ON DELETE CASCADE
+);
+
+-- Favorites
+CREATE TABLE IF NOT EXISTS favorites (
+    user_id TEXT NOT NULL,
+    media_id TEXT NOT NULL,
+    created_at TEXT NOT NULL DEFAULT (datetime('now')),
+    PRIMARY KEY (user_id, media_id),
+    FOREIGN KEY (media_id) REFERENCES media_items(id) ON DELETE CASCADE
+);
+
+-- Share links
+CREATE TABLE IF NOT EXISTS share_links (
+    id TEXT PRIMARY KEY,
+    media_id TEXT NOT NULL,
+    created_by TEXT NOT NULL,
+    token TEXT NOT NULL UNIQUE,
+    password_hash TEXT,
+    expires_at TEXT,
+    view_count INTEGER NOT NULL DEFAULT 0,
+    created_at TEXT NOT NULL DEFAULT (datetime('now')),
+    FOREIGN KEY (media_id) REFERENCES media_items(id) ON DELETE CASCADE
+);
+
+-- Playlists
+CREATE TABLE IF NOT EXISTS playlists (
+    id TEXT PRIMARY KEY,
+    owner_id TEXT NOT NULL,
+    name TEXT NOT NULL,
+    description TEXT,
+    is_public INTEGER NOT NULL DEFAULT 0,
+    is_smart INTEGER NOT NULL DEFAULT 0,
+    filter_query TEXT,
+    created_at TEXT NOT NULL DEFAULT (datetime('now')),
+    updated_at TEXT NOT NULL DEFAULT (datetime('now'))
+);
+
+-- Playlist items
+CREATE TABLE IF NOT EXISTS playlist_items (
+    playlist_id TEXT NOT NULL,
+    media_id TEXT NOT NULL,
+    position INTEGER NOT NULL DEFAULT 0,
+    added_at TEXT NOT NULL DEFAULT (datetime('now')),
+    PRIMARY KEY (playlist_id, media_id),
+    FOREIGN KEY (playlist_id) REFERENCES playlists(id) ON DELETE CASCADE,
+    FOREIGN KEY (media_id) REFERENCES media_items(id) ON DELETE CASCADE
+);
+
+-- Usage events
+CREATE TABLE IF NOT EXISTS usage_events (
+    id TEXT PRIMARY KEY,
+    media_id TEXT,
+    user_id TEXT,
+    event_type TEXT NOT NULL,
+    timestamp TEXT NOT NULL DEFAULT (datetime('now')),
+    duration_secs REAL,
+    context_json TEXT,
+    FOREIGN KEY (media_id) REFERENCES media_items(id) ON DELETE SET NULL
+);
+
+CREATE INDEX IF NOT EXISTS idx_usage_events_media ON usage_events(media_id);
+CREATE INDEX IF NOT EXISTS idx_usage_events_user ON usage_events(user_id);
+CREATE INDEX IF NOT EXISTS idx_usage_events_timestamp ON usage_events(timestamp);
+
+-- Watch history / progress
+CREATE TABLE IF NOT EXISTS watch_history (
+    id TEXT PRIMARY KEY,
+    user_id TEXT NOT NULL,
+    media_id TEXT NOT NULL,
+    progress_secs REAL NOT NULL DEFAULT 0,
+    last_watched TEXT NOT NULL DEFAULT (datetime('now')),
+    UNIQUE(user_id, media_id),
+    FOREIGN KEY (media_id) REFERENCES media_items(id) ON DELETE CASCADE
+);
+
+-- Subtitles
+CREATE TABLE IF NOT EXISTS subtitles (
+    id TEXT PRIMARY KEY,
+    media_id TEXT NOT NULL,
+    language TEXT,
+    format TEXT NOT NULL,
+    file_path TEXT,
+    is_embedded INTEGER NOT NULL DEFAULT 0,
+    track_index INTEGER,
+    offset_ms INTEGER NOT NULL DEFAULT 0,
+    created_at TEXT NOT NULL DEFAULT (datetime('now')),
+    FOREIGN KEY (media_id) REFERENCES media_items(id) ON DELETE CASCADE
+);
+
+CREATE INDEX IF NOT EXISTS idx_subtitles_media ON subtitles(media_id);
+
+-- External metadata (enrichment)
+CREATE TABLE IF NOT EXISTS external_metadata (
+    id TEXT PRIMARY KEY,
+    media_id TEXT NOT NULL,
+    source TEXT NOT NULL,
+    external_id TEXT,
+    metadata_json TEXT NOT NULL DEFAULT '{}',
+    confidence REAL NOT NULL DEFAULT 0.0,
+    last_updated TEXT NOT NULL DEFAULT (datetime('now')),
+    FOREIGN KEY (media_id) REFERENCES media_items(id) ON DELETE CASCADE
+);
+
+CREATE INDEX IF NOT EXISTS idx_external_metadata_media ON external_metadata(media_id);
+
+-- Transcode sessions
+CREATE TABLE IF NOT EXISTS transcode_sessions (
+    id TEXT PRIMARY KEY,
+    media_id TEXT NOT NULL,
+    user_id TEXT,
+    profile TEXT NOT NULL,
+    cache_path TEXT NOT NULL,
+    status TEXT NOT NULL DEFAULT 'pending',
+    progress REAL NOT NULL DEFAULT 0.0,
+    error_message TEXT,
+    created_at TEXT NOT NULL DEFAULT (datetime('now')),
+    expires_at TEXT,
+    FOREIGN KEY (media_id) REFERENCES media_items(id) ON DELETE CASCADE
+);
+
+CREATE INDEX IF NOT EXISTS idx_transcode_sessions_media ON transcode_sessions(media_id);
diff --git a/migrations/sqlite/V9__fix_indexes_and_constraints.sql b/migrations/sqlite/V9__fix_indexes_and_constraints.sql
new file mode 100644
index 0000000..432f35a
--- /dev/null
+++ b/migrations/sqlite/V9__fix_indexes_and_constraints.sql
@@ -0,0 +1,18 @@
+-- Drop redundant indexes (already covered by UNIQUE constraints)
+DROP INDEX IF EXISTS idx_users_username;
+DROP INDEX IF EXISTS idx_user_libraries_user_id;
+
+-- Add missing indexes for comments table
+CREATE INDEX IF NOT EXISTS idx_comments_media ON comments(media_id);
+CREATE INDEX IF NOT EXISTS idx_comments_parent ON comments(parent_comment_id);
+
+-- Remove duplicates before adding unique index (keep the first row)
+DELETE FROM external_metadata
+WHERE rowid NOT IN (
+    SELECT MIN(rowid)
+    FROM external_metadata
+    GROUP BY media_id, source
+);
+
+-- Add unique index for external_metadata to prevent duplicates
+CREATE UNIQUE INDEX IF NOT EXISTS uq_external_metadata_source ON external_metadata(media_id, source);