diff --git a/db/bootstrap.sql b/db/bootstrap.sql
index bd76d4c6..86b863f5 100644
--- a/db/bootstrap.sql
+++ b/db/bootstrap.sql
@@ -7,7 +7,11 @@
 -- Enable required extensions
 CREATE EXTENSION IF NOT EXISTS "uuid-ossp";
 CREATE EXTENSION IF NOT EXISTS "pgcrypto";
-CREATE EXTENSION IF NOT EXISTS "vector"; -- pgvector for semantic memory embeddings
+DO $$ BEGIN
+  CREATE EXTENSION IF NOT EXISTS "vector";
+EXCEPTION WHEN OTHERS THEN
+  RAISE NOTICE 'pgvector not available — vector columns will be skipped. Install pgvector for semantic search.';
+END $$; -- pgvector for semantic memory embeddings (optional)
 
 -- ============================================================================
 -- SYSTEM LOGS TABLE
@@ -243,8 +247,16 @@ CREATE INDEX IF NOT EXISTS idx_tasks_priority ON tasks(priority DESC);
 CREATE INDEX IF NOT EXISTS idx_tasks_created_at ON tasks(created_at DESC);
 CREATE INDEX IF NOT EXISTS idx_tasks_task_type ON tasks(task_type);
 
--- User attribution columns — allow quota deduction and identity surfacing without a join
+-- Ensure all tasks columns exist (safe to re-run — idempotent via IF NOT EXISTS)
 ALTER TABLE tasks
+    ADD COLUMN IF NOT EXISTS task_type         VARCHAR(100) NOT NULL DEFAULT 'workflow_step',
+    ADD COLUMN IF NOT EXISTS input             JSONB        NOT NULL DEFAULT '{}',
+    ADD COLUMN IF NOT EXISTS output            JSONB,
+    ADD COLUMN IF NOT EXISTS retry_count       INTEGER      NOT NULL DEFAULT 0,
+    ADD COLUMN IF NOT EXISTS max_retries       INTEGER      NOT NULL DEFAULT 3,
+    ADD COLUMN IF NOT EXISTS timeout_seconds   INTEGER      NOT NULL DEFAULT 300,
+    ADD COLUMN IF NOT EXISTS idempotency_key   VARCHAR(255),
+    ADD COLUMN IF NOT EXISTS started_at        TIMESTAMPTZ,
     ADD COLUMN IF NOT EXISTS created_by        VARCHAR(255) DEFAULT NULL,
     ADD COLUMN IF NOT EXISTS user_email        VARCHAR(255) DEFAULT NULL,
     ADD COLUMN IF NOT EXISTS user_display_name VARCHAR(255) DEFAULT NULL;
@@ -1146,7 +1158,7 @@ CREATE TABLE IF NOT EXISTS agent_memories (
     is_promoted     BOOLEAN     NOT NULL DEFAULT false,
     promoted_at     TIMESTAMPTZ,
     promoted_by     TEXT,
-    embedding       vector(1536),  -- text-embedding-3-small / ada-002 dimensions
+    -- embedding column added conditionally below (requires pgvector)
     name            TEXT,
     description     TEXT,
     is_pristine     BOOLEAN     NOT NULL DEFAULT false,
@@ -1216,6 +1228,14 @@ CREATE INDEX IF NOT EXISTS idx_agent_memories_parent
     ON agent_memories(parent_id)
     WHERE parent_id IS NOT NULL;
 
+-- Add embedding column to agent_memories when pgvector is available
+DO $$ BEGIN
+    IF EXISTS (SELECT 1 FROM pg_extension WHERE extname = 'vector') THEN
+        ALTER TABLE agent_memories ADD COLUMN IF NOT EXISTS embedding vector(1536);
+    END IF;
+EXCEPTION WHEN OTHERS THEN NULL;
+END $$;
+
 -- HNSW index for fast approximate nearest-neighbour semantic search
 -- Only created when pgvector is available (will silently skip if column missing)
 DO $$ BEGIN
@@ -3276,7 +3296,7 @@ CREATE TABLE IF NOT EXISTS rag_chunks (
     corpus_id   VARCHAR(80)   NOT NULL REFERENCES rag_corpora(corpus_id) ON DELETE CASCADE,
     source_id   VARCHAR(80)   REFERENCES rag_sources(source_id) ON DELETE CASCADE,
     content     TEXT          NOT NULL,
-    embedding   vector(1536),
+    -- embedding column added conditionally below (requires pgvector)
     chunk_index INTEGER       NOT NULL DEFAULT 0,
     token_count INTEGER,
     metadata    JSONB         NOT NULL DEFAULT '{}',
@@ -3287,6 +3307,14 @@ CREATE INDEX IF NOT EXISTS idx_rag_chunks_corpus     ON rag_chunks(corpus_id);
 CREATE INDEX IF NOT EXISTS idx_rag_chunks_source     ON rag_chunks(source_id) WHERE source_id IS NOT NULL;
 CREATE INDEX IF NOT EXISTS idx_rag_chunks_created_at ON rag_chunks(created_at DESC);
 
+-- Add embedding column to rag_chunks when pgvector is available
+DO $$ BEGIN
+    IF EXISTS (SELECT 1 FROM pg_extension WHERE extname = 'vector') THEN
+        ALTER TABLE rag_chunks ADD COLUMN IF NOT EXISTS embedding vector(1536);
+    END IF;
+EXCEPTION WHEN OTHERS THEN NULL;
+END $$;
+
 -- ============================================================================
 -- CHAT SESSIONS & MESSAGES
 -- ============================================================================
diff --git a/db/db-verify.sh b/db/db-verify.sh
index edeb0083..93b57bdb 100755
--- a/db/db-verify.sh
+++ b/db/db-verify.sh
@@ -130,9 +130,15 @@ info "bootstrap.sql + $MIGRATION_COUNT migration file(s)"
 # Column names always start with lowercase in our schema; SQL keywords
 # (CONSTRAINT, PRIMARY, UNIQUE, etc.) are uppercase — used to skip them.
 EXPECTED_RAW=$(awk '
-  FNR == 1 { alter_tbl = ""; in_create = 0 }
+  FNR == 1 { alter_tbl = ""; in_create = 0; in_do_block = 0 }
+
+  # Track DO $$ blocks — any ALTER TABLE inside them is procedural, not schema DDL
+  /^DO \$\$/ || /^DO\$\$/ { in_do_block = 1 }
+  in_do_block && /END \$\$/ { in_do_block = 0; alter_tbl = ""; next }
+  in_do_block { next }
 
   /^CREATE TABLE IF NOT EXISTS / {
+    alter_tbl = ""   # reset stale alter context
     tbl = $6
     gsub(/"/, "", tbl); gsub(/\(/, "", tbl); gsub(/;/, "", tbl)
     gsub(/public\./, "", tbl)
@@ -152,12 +158,19 @@ EXPECTED_RAW=$(awk '
     next
   }
 
+  # Top-level statements that are not ALTER TABLE reset the alter context
+  /^(CREATE|INSERT|UPDATE|DELETE|DROP|COMMENT|GRANT|REVOKE|SET|SELECT|WITH|DO) / {
+    alter_tbl = ""
+  }
+
   /^ALTER TABLE / {
     alter_tbl = $3
     gsub(/"/, "", alter_tbl); gsub(/public\./, "", alter_tbl)
   }
 
+  # Only match ADD COLUMN when alter_tbl is set (i.e., inside a real ALTER TABLE)
   /ADD COLUMN IF NOT EXISTS / {
+    if (alter_tbl == "") next
     n = split($0, a, "ADD COLUMN IF NOT EXISTS ")
     if (n < 2) next
     col = a[2]
@@ -165,9 +178,12 @@ EXPECTED_RAW=$(awk '
     split(col, b, " ")
     col = b[1]
     gsub(/,/, "", col); gsub(/;/, "", col); gsub(/"/, "", col)
-    if (alter_tbl != "" && col != "")
+    if (col != "")
       print "C:" alter_tbl "." col
   }
+
+  # Reset alter_tbl at end of statement (line ends with ;)
+  /;[[:space:]]*$/ && !/^[[:space:]]/ { if ($1 != "ALTER") alter_tbl = "" }
 ' "${SQL_FILES[@]}" | sort -u)
 
 EXPECTED_TABLES=$(echo "$EXPECTED_RAW" | grep '^T:' | sed 's/^T://')
@@ -210,12 +226,19 @@ if [[ -z "$ACTUAL_COLS" || "$AC" -lt 50 ]]; then
   exit 1
 fi
 
+# Write to temp files to avoid set -o pipefail + grep -q SIGPIPE false negatives.
+# When grep -q finds a match and exits early, echo gets SIGPIPE (exit 141).
+# pipefail then returns 141 (non-zero) even though the match was found.
+_TMP_TABLES=$(mktemp) && echo "$ACTUAL_TABLES" > "$_TMP_TABLES"
+_TMP_COLS=$(mktemp)   && echo "$ACTUAL_COLS"   > "$_TMP_COLS"
+trap 'rm -f "$_TMP_TABLES" "$_TMP_COLS"' EXIT
+
 # ── Table comparison ───────────────────────────────────────────────────────────
 section "Tables"
 
 while IFS= read -r tbl; do
   [[ -z "$tbl" ]] && continue
-  if echo "$ACTUAL_TABLES" | grep -Fxq "$tbl"; then
+  if grep -Fxq "$tbl" "$_TMP_TABLES"; then
     ok "$tbl"
   else
     fail "$tbl  ← NOT IN DB"
@@ -225,7 +248,7 @@ done <<< "$EXPECTED_TABLES"
 
 while IFS= read -r tbl; do
   [[ -z "$tbl" ]] && continue
-  if ! echo "$EXPECTED_TABLES" | grep -Fxq "$tbl"; then
+  if ! grep -Fxq "$tbl" <<< "$EXPECTED_TABLES"; then
     extra "$tbl  (in DB, not in any SQL file)"
     ((EXTRA_COUNT++)) || true
   fi
@@ -245,7 +268,7 @@ while IFS= read -r col; do
   done
   $skip && continue
 
-  if ! echo "$ACTUAL_COLS" | grep -Fxq "$col"; then
+  if ! grep -Fxq "$col" "$_TMP_COLS"; then
     fail "$col  ← MISSING"
     MISSING_COLS+=("$col")
     ((FOUND_COL_ISSUES++)) || true
diff --git a/db/migrations/034_marketplace_and_source_model.sql b/db/migrations/034_marketplace_and_source_model.sql
index d58d47b0..e1c217f0 100644
--- a/db/migrations/034_marketplace_and_source_model.sql
+++ b/db/migrations/034_marketplace_and_source_model.sql
@@ -106,3 +106,8 @@ CREATE TABLE IF NOT EXISTS benchmark_promotion_log (
 
 CREATE INDEX IF NOT EXISTS idx_benchmark_promotion_log_agent_id
     ON benchmark_promotion_log(agent_id);
+
+-- Idempotent guards: add columns that CREATE TABLE IF NOT EXISTS skips on existing tables
+ALTER TABLE marketplace_agents
+    ADD COLUMN IF NOT EXISTS is_malicious  BOOLEAN NOT NULL DEFAULT FALSE,
+    ADD COLUMN IF NOT EXISTS scan_notes    TEXT;