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+-- ============================================================================
+--   W A R N U N G  –  K I – G E N E R I E R T E S   D A T E N B A N K – S C H E M A
+--
+--   Dieses SQL-Schema / diese Daten wurden vollständig von einer KI generiert.
+--   Experiment-Key: run_17_gates_default
+--
+--   WICHTIG:
+--   • Rein experimentell – KEINE Qualitätssicherung, KEINE Tests
+--   • KEIN PRODUKTIVEINSATZ – auch nicht in Test- oder Staging-Umgebungen!
+--   • Kann Datenverlust, Inkonsistenzen, Sicherheitslücken oder Abstürze verursachen
+--   • Nur für Forschung, Demonstration und Lernzwecke gedacht
+--
+--   Verwenden auf eigene Gefahr!
+-- ============================================================================
+-- Datenbank-Dialekt: PostgreSQL 16+
+-- Kompatibilität: PostgreSQL >= 15 empfohlen
+
+CREATE TABLE runs (
+    run_id            BIGSERIAL    NOT NULL,
+    run_label         TEXT         NOT NULL,
+    experiment_key    TEXT         NOT NULL,
+    setup_fingerprint TEXT         NOT NULL,
+    policy_hash       TEXT         NOT NULL,
+    gate_version      TEXT         NOT NULL,
+    mode              TEXT         NOT NULL DEFAULT 'warn',
+    started_at        TIMESTAMPTZ  NOT NULL,
+    completed_at      TIMESTAMPTZ,
+    decision_card_url TEXT,
+    notes             TEXT,
+    CONSTRAINT runs_pkey PRIMARY KEY (run_id),
+    CONSTRAINT runs_run_label_key UNIQUE (run_label),
+    CONSTRAINT runs_mode_chk CHECK (mode IN ('warn', 'observe', 'enforce')),
+    CONSTRAINT runs_timeline_chk CHECK (completed_at IS NULL OR completed_at >= started_at)
+);
+
+COMMENT ON TABLE runs IS 'Metadaten zu Gate-V1-Experimentläufen (z. B. Run #14–#17).';
+
+CREATE TABLE strata (
+    stratum_code TEXT    NOT NULL,
+    description  TEXT    NOT NULL,
+    is_pinned    BOOLEAN NOT NULL,
+    near_expiry  BOOLEAN NOT NULL,
+    CONSTRAINT strata_pkey PRIMARY KEY (stratum_code)
+);
+
+COMMENT ON TABLE strata IS 'Referenztabelle für Strata (pinned, unpinned, near-expiry, ...).';
+
+CREATE TABLE log_entries (
+    log_id                  BIGSERIAL    NOT NULL,
+    run_id                  BIGINT       NOT NULL,
+    stratum_code            TEXT         NOT NULL,
+    recorded_at             TIMESTAMPTZ  NOT NULL DEFAULT NOW(),
+    retry_taken             BOOLEAN      NOT NULL,
+    retry_total_overhead_ms INTEGER      NOT NULL,
+    expires_at_dist_hours   NUMERIC(8,3) NOT NULL,
+    delta_t                 NUMERIC(9,3) NOT NULL,
+    CONSTRAINT log_entries_pkey PRIMARY KEY (log_id),
+    CONSTRAINT log_entries_run_fk FOREIGN KEY (run_id)
+        REFERENCES runs (run_id) ON DELETE CASCADE ON UPDATE RESTRICT,
+    CONSTRAINT log_entries_stratum_fk FOREIGN KEY (stratum_code)
+        REFERENCES strata (stratum_code) ON DELETE RESTRICT ON UPDATE CASCADE,
+    CONSTRAINT log_entries_retry_overhead_chk CHECK (retry_total_overhead_ms BETWEEN 0 AND 1000),
+    CONSTRAINT log_entries_expires_dist_chk CHECK (expires_at_dist_hours BETWEEN -720 AND 720),
+    CONSTRAINT log_entries_delta_t_chk CHECK (delta_t BETWEEN -500 AND 500)
+);
+
+COMMENT ON TABLE log_entries IS 'Zentrale Log-Tabelle für Gate-V1-Entscheidungsdaten (Δt, Retry-Overhead etc.).';
+COMMENT ON COLUMN log_entries.delta_t IS 'Gemessene Δt-Abweichung in Millisekunden (negativ bedeutet zu früh).';
+COMMENT ON COLUMN log_entries.expires_at_dist_hours IS 'Zeitabstand bis zum Expiry (Stunden, kann negativ sein).';
+
+CREATE INDEX log_entries_run_stratum_idx
+    ON log_entries (run_id, stratum_code);
+
+CREATE INDEX log_entries_stratum_delta_t_idx
+    ON log_entries (stratum_code, delta_t);
+
+CREATE INDEX log_entries_retry_taken_idx
+    ON log_entries (stratum_code, retry_taken)
+    WHERE retry_taken = TRUE;