diff --git a/server/migrations/214_chat_session_project.up.sql b/server/migrations/214_chat_session_project.up.sql
index 880d4f67d..86db0e7cf 100644
--- a/server/migrations/214_chat_session_project.up.sql
+++ b/server/migrations/214_chat_session_project.up.sql
@@ -4,5 +4,11 @@
 -- Create/delete handlers serialize on the project row, project deletion clears
 -- existing references, and daemon claim revalidates workspace ownership before
 -- injecting any context.
+--
+-- IF NOT EXISTS because this migration was first shipped as 213_chat_session_project
+-- and later renumbered to 214 (#5868, dodging a prefix collision). Environments
+-- that already applied it under the old 213 name have the column but not the 214
+-- version row, so the runner re-applies it under the new name; without the guard
+-- that re-run fails with "column already exists" (SQLSTATE 42701) and blocks deploy.
 ALTER TABLE chat_session
-  ADD COLUMN project_id UUID;
+  ADD COLUMN IF NOT EXISTS project_id UUID;
diff --git a/server/migrations/213_vcs_integration.down.sql b/server/migrations/216_vcs_integration.down.sql
similarity index 100%
rename from server/migrations/213_vcs_integration.down.sql
rename to server/migrations/216_vcs_integration.down.sql
diff --git a/server/migrations/213_vcs_integration.up.sql b/server/migrations/216_vcs_integration.up.sql
similarity index 98%
rename from server/migrations/213_vcs_integration.up.sql
rename to server/migrations/216_vcs_integration.up.sql
index f15f2be6e..1892030e4 100644
--- a/server/migrations/213_vcs_integration.up.sql
+++ b/server/migrations/216_vcs_integration.up.sql
@@ -17,7 +17,7 @@
 -- rows below in a single atomic statement). The inline UNIQUE / PRIMARY KEY
 -- constraints stay — they back the ON CONFLICT upsert targets in vcs.sql.
 -- Secondary indexes live in follow-up single-statement CREATE INDEX
--- CONCURRENTLY migrations (214-218), which cannot share a file with these
+-- CONCURRENTLY migrations (217-221), which cannot share a file with these
 -- CREATE TABLEs.
 
 CREATE TABLE IF NOT EXISTS vcs_connection (
diff --git a/server/migrations/214_vcs_connection_workspace_index.down.sql b/server/migrations/217_vcs_connection_workspace_index.down.sql
similarity index 100%
rename from server/migrations/214_vcs_connection_workspace_index.down.sql
rename to server/migrations/217_vcs_connection_workspace_index.down.sql
diff --git a/server/migrations/214_vcs_connection_workspace_index.up.sql b/server/migrations/217_vcs_connection_workspace_index.up.sql
similarity index 100%
rename from server/migrations/214_vcs_connection_workspace_index.up.sql
rename to server/migrations/217_vcs_connection_workspace_index.up.sql
diff --git a/server/migrations/215_vcs_pull_request_workspace_index.down.sql b/server/migrations/218_vcs_pull_request_workspace_index.down.sql
similarity index 100%
rename from server/migrations/215_vcs_pull_request_workspace_index.down.sql
rename to server/migrations/218_vcs_pull_request_workspace_index.down.sql
diff --git a/server/migrations/215_vcs_pull_request_workspace_index.up.sql b/server/migrations/218_vcs_pull_request_workspace_index.up.sql
similarity index 100%
rename from server/migrations/215_vcs_pull_request_workspace_index.up.sql
rename to server/migrations/218_vcs_pull_request_workspace_index.up.sql
diff --git a/server/migrations/216_vcs_pull_request_connection_index.down.sql b/server/migrations/219_vcs_pull_request_connection_index.down.sql
similarity index 100%
rename from server/migrations/216_vcs_pull_request_connection_index.down.sql
rename to server/migrations/219_vcs_pull_request_connection_index.down.sql
diff --git a/server/migrations/216_vcs_pull_request_connection_index.up.sql b/server/migrations/219_vcs_pull_request_connection_index.up.sql
similarity index 100%
rename from server/migrations/216_vcs_pull_request_connection_index.up.sql
rename to server/migrations/219_vcs_pull_request_connection_index.up.sql
diff --git a/server/migrations/217_issue_vcs_pull_request_pr_index.down.sql b/server/migrations/220_issue_vcs_pull_request_pr_index.down.sql
similarity index 100%
rename from server/migrations/217_issue_vcs_pull_request_pr_index.down.sql
rename to server/migrations/220_issue_vcs_pull_request_pr_index.down.sql
diff --git a/server/migrations/217_issue_vcs_pull_request_pr_index.up.sql b/server/migrations/220_issue_vcs_pull_request_pr_index.up.sql
similarity index 100%
rename from server/migrations/217_issue_vcs_pull_request_pr_index.up.sql
rename to server/migrations/220_issue_vcs_pull_request_pr_index.up.sql
diff --git a/server/migrations/218_vcs_commit_status_lookup_index.down.sql b/server/migrations/221_vcs_commit_status_lookup_index.down.sql
similarity index 100%
rename from server/migrations/218_vcs_commit_status_lookup_index.down.sql
rename to server/migrations/221_vcs_commit_status_lookup_index.down.sql
diff --git a/server/migrations/218_vcs_commit_status_lookup_index.up.sql b/server/migrations/221_vcs_commit_status_lookup_index.up.sql
similarity index 100%
rename from server/migrations/218_vcs_commit_status_lookup_index.up.sql
rename to server/migrations/221_vcs_commit_status_lookup_index.up.sql