feat(db): add Phase 2 skill tables migration

server/skillhub-app/src/main/resources/db/migration/V2__phase2_skill_tables.sql

@@ -0,0 +1,103 @@
+-- V2__phase2_skill_tables.sql
+-- Phase 2: 命名空间 + Skill 核心链路
+
+-- 技能主表
+CREATE TABLE skill (
+    id BIGSERIAL PRIMARY KEY,
+    namespace_id BIGINT NOT NULL REFERENCES namespace(id),
+    slug VARCHAR(128) NOT NULL,
+    display_name VARCHAR(256),
+    summary VARCHAR(512),
+    owner_id BIGINT NOT NULL REFERENCES user_account(id),
+    source_skill_id BIGINT,
+    visibility VARCHAR(32) NOT NULL DEFAULT 'PUBLIC',
+    status VARCHAR(32) NOT NULL DEFAULT 'ACTIVE',
+    latest_version_id BIGINT,
+    download_count BIGINT NOT NULL DEFAULT 0,
+    star_count INT NOT NULL DEFAULT 0,
+    rating_avg DECIMAL(3,2) NOT NULL DEFAULT 0.00,
+    rating_count INT NOT NULL DEFAULT 0,
+    created_by BIGINT REFERENCES user_account(id),
+    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_by BIGINT REFERENCES user_account(id),
+    updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    UNIQUE(namespace_id, slug)
+);
+
+CREATE INDEX idx_skill_namespace_status ON skill(namespace_id, status);
+
+-- 技能版本表
+CREATE TABLE skill_version (
+    id BIGSERIAL PRIMARY KEY,
+    skill_id BIGINT NOT NULL REFERENCES skill(id),
+    version VARCHAR(64) NOT NULL,
+    status VARCHAR(32) NOT NULL DEFAULT 'DRAFT',
+    changelog TEXT,
+    parsed_metadata_json JSONB,
+    manifest_json JSONB,
+    file_count INT NOT NULL DEFAULT 0,
+    total_size BIGINT NOT NULL DEFAULT 0,
+    published_at TIMESTAMP,
+    created_by BIGINT REFERENCES user_account(id),
+    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    UNIQUE(skill_id, version)
+);
+
+CREATE INDEX idx_skill_version_skill_status ON skill_version(skill_id, status);
+
+ALTER TABLE skill ADD CONSTRAINT fk_skill_latest_version
+    FOREIGN KEY (latest_version_id) REFERENCES skill_version(id);
+
+-- 技能文件表
+CREATE TABLE skill_file (
+    id BIGSERIAL PRIMARY KEY,
+    version_id BIGINT NOT NULL REFERENCES skill_version(id),
+    file_path VARCHAR(512) NOT NULL,
+    file_size BIGINT NOT NULL,
+    content_type VARCHAR(128),
+    sha256 VARCHAR(64) NOT NULL,
+    storage_key VARCHAR(512) NOT NULL,
+    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    UNIQUE(version_id, file_path)
+);
+
+-- 技能标签表
+CREATE TABLE skill_tag (
+    id BIGSERIAL PRIMARY KEY,
+    skill_id BIGINT NOT NULL REFERENCES skill(id),
+    tag_name VARCHAR(64) NOT NULL,
+    version_id BIGINT NOT NULL REFERENCES skill_version(id),
+    created_by BIGINT REFERENCES user_account(id),
+    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    UNIQUE(skill_id, tag_name)
+);
+
+-- 搜索文档表
+CREATE TABLE skill_search_document (
+    id BIGSERIAL PRIMARY KEY,
+    skill_id BIGINT NOT NULL UNIQUE REFERENCES skill(id),
+    namespace_id BIGINT NOT NULL,
+    namespace_slug VARCHAR(64) NOT NULL,
+    owner_id BIGINT NOT NULL,
+    title VARCHAR(256),
+    summary VARCHAR(512),
+    keywords VARCHAR(512),
+    search_text TEXT,
+    visibility VARCHAR(32) NOT NULL,
+    status VARCHAR(32) NOT NULL,
+    updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+ALTER TABLE skill_search_document
+ADD COLUMN search_vector tsvector
+GENERATED ALWAYS AS (
+    setweight(to_tsvector('simple', coalesce(title, '')), 'A') ||
+    setweight(to_tsvector('simple', coalesce(summary, '')), 'B') ||
+    setweight(to_tsvector('simple', coalesce(keywords, '')), 'B') ||
+    setweight(to_tsvector('simple', coalesce(search_text, '')), 'C')
+) STORED;
+
+CREATE INDEX idx_search_vector ON skill_search_document USING GIN (search_vector);
+CREATE INDEX idx_search_doc_namespace ON skill_search_document(namespace_id);
+CREATE INDEX idx_search_doc_visibility ON skill_search_document(visibility);