Add log schema and documentation

schemas/04_log.sql

@@ -0,0 +1,76 @@
+-- ============================================
+-- SCHEMA LOG - Sistema TZZR
+-- Log inmutable de mensajes
+-- ============================================
+
+DROP SCHEMA IF EXISTS log CASCADE;
+CREATE SCHEMA log;
+
+-- Extensiones
+CREATE EXTENSION IF NOT EXISTS pgcrypto;
+
+-- Tipos
+CREATE TYPE log.actor_type AS ENUM ('user', 'agent', 'orchestrator', 'system', 'tool');
+
+-- Tabla principal
+CREATE TABLE log.messages (
+    id              BIGSERIAL PRIMARY KEY,
+    hash            CHAR(64) UNIQUE NOT NULL,
+    session_hash    CHAR(64) NOT NULL,
+    sender_type     log.actor_type NOT NULL,
+    sender_id       CHAR(64) NOT NULL,
+    receiver_type   log.actor_type NOT NULL,
+    receiver_id     CHAR(64) NOT NULL,
+    leader_id       CHAR(64),
+    role            TEXT,
+    content         TEXT NOT NULL,
+    attachments     JSONB DEFAULT '{}',
+    prev_hash       CHAR(64),
+    context_hashes  CHAR(64)[] DEFAULT '{}',
+    hashtags        CHAR(64)[] DEFAULT '{}',
+    created_at      TIMESTAMPTZ DEFAULT NOW()
+);
+
+-- Índices
+CREATE INDEX idx_messages_session ON log.messages(session_hash);
+CREATE INDEX idx_messages_sender ON log.messages(sender_id);
+CREATE INDEX idx_messages_receiver ON log.messages(receiver_id);
+CREATE INDEX idx_messages_prev ON log.messages(prev_hash);
+CREATE INDEX idx_messages_created ON log.messages(created_at);
+CREATE INDEX idx_messages_hashtags ON log.messages USING gin(hashtags);
+
+-- Función SHA256
+CREATE OR REPLACE FUNCTION log.sha256(data TEXT) RETURNS CHAR(64) AS $$
+BEGIN
+    RETURN encode(digest(data, 'sha256'), 'hex');
+END;
+$$ LANGUAGE plpgsql IMMUTABLE;
+
+-- Protección: no UPDATE
+CREATE OR REPLACE FUNCTION log.prevent_update() RETURNS TRIGGER AS $$
+BEGIN
+    RAISE EXCEPTION 'UPDATE no permitido en log.messages';
+END;
+$$ LANGUAGE plpgsql;
+
+-- Protección: no DELETE
+CREATE OR REPLACE FUNCTION log.prevent_delete() RETURNS TRIGGER AS $$
+BEGIN
+    RAISE EXCEPTION 'DELETE no permitido en log.messages';
+END;
+$$ LANGUAGE plpgsql;
+
+-- Triggers de protección
+CREATE TRIGGER protect_update BEFORE UPDATE ON log.messages
+    FOR EACH ROW EXECUTE FUNCTION log.prevent_update();
+
+CREATE TRIGGER protect_delete BEFORE DELETE ON log.messages
+    FOR EACH ROW EXECUTE FUNCTION log.prevent_delete();
+
+-- Permisos
+GRANT USAGE ON SCHEMA log TO tzzr;
+GRANT SELECT, INSERT ON log.messages TO tzzr;
+GRANT USAGE ON SEQUENCE log.messages_id_seq TO tzzr;
+
+-- Verificación
+SELECT 'Schema log creado' as status;