feat(migrations): Harden task audit tracking and optimize article templates

- Added migration to harden task audit tracking by modifying audit_logs and related tables.
- Introduced operator_id to several tables for better tracking of actions.
- Updated article_templates with new prompt templates for various article types, enhancing content generation.
- Created prompt_rules and schedule_tasks tables to manage content generation rules and scheduling.
- Added foreign key constraints to articles for better data integrity.

server/migrations/20260401180000_create_prompt_rules.up.sql

@@ -0,0 +1,28 @@
+CREATE TABLE prompt_rule_groups (
+    id          BIGSERIAL PRIMARY KEY,
+    tenant_id   BIGINT NOT NULL REFERENCES tenants(id),
+    name        VARCHAR(100) NOT NULL,
+    sort_order  INT NOT NULL DEFAULT 0,
+    created_at  TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at  TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    deleted_at  TIMESTAMPTZ
+);
+CREATE INDEX idx_prompt_rule_group_tenant ON prompt_rule_groups(tenant_id, sort_order);
+
+CREATE TABLE prompt_rules (
+    id              BIGSERIAL PRIMARY KEY,
+    tenant_id       BIGINT NOT NULL REFERENCES tenants(id),
+    group_id        BIGINT REFERENCES prompt_rule_groups(id),
+    name            VARCHAR(100) NOT NULL,
+    prompt_content  TEXT NOT NULL,
+    scene           VARCHAR(50),
+    default_tone    VARCHAR(30),
+    default_word_count INT,
+    status          VARCHAR(20) NOT NULL DEFAULT 'enabled',
+    created_at      TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at      TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    deleted_at      TIMESTAMPTZ
+);
+CREATE INDEX idx_prompt_rule_tenant ON prompt_rules(tenant_id, created_at DESC);
+CREATE INDEX idx_prompt_rule_tenant_status ON prompt_rules(tenant_id, status) WHERE deleted_at IS NULL;
+CREATE INDEX idx_prompt_rule_group ON prompt_rules(group_id) WHERE deleted_at IS NULL;