v1.13.20-drop-legacy-cols: final phase of v1.13.0 strangler-fig

Removes the dual-write into messages.tool_calls / messages.tool_results JSON
columns and drops the columns. message_parts is now the only source of truth
for tool calls and tool results.

10 dual-write sites stripped (5 in tool-phase.ts, 2 in routes/skills.ts, 2 in
routes/messages.ts, 1 in routes/chats.ts fork-clone). The recon-driven grep
caught 2 sites beyond the original v1.13.2 roadmap inventory and an extra
fixture file (tool_cost_stats.test.ts) with a direct legacy-column INSERT.

messages_with_parts view rewritten to parts-only subselects (COALESCE
fallbacks gone). View runs via CREATE OR REPLACE so it lands before the
column DROPs in startup DDL — Postgres rejects column-drop on view-referenced
cols. v1.12.1 cleanup DO block (DROP CONSTRAINT messages_status_check /
messages_role_check) removed; those one-shots have done their work.

Adversarial review caught a runtime bug the green test suite missed: the
discard_stale endpoint (chats.ts) had a RETURNING ... tool_calls, tool_results
clause that would have crashed on every 60s-no-token-activity recovery in
production. Fixed by switching to two-step UPDATE returning id, then SELECT
from messages_with_parts so parts-synthesized fields keep flowing on the wire.

Message API type retains tool_calls? / tool_results? — the view synthesizes
those keys from parts so the wire shape is unchanged; frontend reads need no
update. Override on the original v1.13.2 plan, captured in the openspec
proposal.

339/339 server tests passing (including 7 DB-integration tests that applied
the schema migration to a live DB and ran the parts-only view end-to-end).
tsc + web build clean.

Pairs with v1.13.0-ai-sdk-v6 (introduced the dual-write) and v1.13.1-B (moved
the read path to messages_with_parts). Umbrella v1.13 tag ships on this same
commit, marking the strangler-fig closed.

CLAUDE.md picks up Sam's pre-existing edits documenting tag-naming and
CHANGELOG conventions — both already in use by v1.13.19 / v1.13.20.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/server/src/schema.sql

@@ -97,49 +97,42 @@ END $$;
 
 -- v1.13.1-B: read-path view. Read sites SELECT FROM messages_with_parts
 -- instead of messages so tool_calls / tool_results / reasoning_parts come
--- from the granular message_parts table. The COALESCE means pre-v1.13.0
--- history (no parts rows) still resolves via the legacy JSON columns; the
--- dual-write from v1.13.0 keeps both in sync for all rows written since.
--- Writes continue to target `messages` directly — the view is read-only.
--- Shapes match the in-memory ToolCall / ToolResult types: tool_calls is a
--- jsonb array of {id, name, args}, tool_results is a single jsonb object
--- {tool_call_id, output, truncated, error?}. reasoning_parts is new — only
--- consumed by the inference history fetch (payload.ts) so v1.13.1-C can
--- wire reasoning into the model payload. Not surfaced in external APIs yet.
+-- from the granular message_parts table.
+-- v1.13.20: post column-drop. The legacy COALESCE fallback over
+-- messages.tool_calls / messages.tool_results was removed because those
+-- columns no longer exist on the table (see the ALTER TABLE DROP COLUMN
+-- statements below). Writes continue to target `messages` directly — the
+-- view is read-only. Shapes match the in-memory ToolCall / ToolResult
+-- types: tool_calls is a jsonb array of {id, name, args}, tool_results is
+-- a single jsonb object {tool_call_id, output, truncated, error?}.
+-- reasoning_parts is consumed by the inference history fetch (payload.ts)
+-- for v1.13.1-C reasoning round-tripping. Not surfaced in external APIs.
 CREATE OR REPLACE VIEW messages_with_parts AS
 SELECT
   m.id, m.session_id, m.chat_id, m.role, m.content, m.kind, m.status,
   m.last_seq, m.tokens_used, m.ctx_used, m.ctx_max,
   m.started_at, m.finished_at, m.created_at, m.metadata,
   m.summary, m.tail_start_id, m.compacted_at,
-  -- v1.13.4: prune semantics need to distinguish "no parts row exists"
-  -- (pre-v1.13.0 fallback to legacy column) from "all parts hidden"
-  -- (prune intended — return null/empty so the row drops from the model
-  -- payload). A naive COALESCE would fall back to the legacy column when
-  -- every part is hidden, undoing the prune. CASE on EXISTS(any kind)
-  -- splits the two cases.
-  CASE
-    WHEN EXISTS (SELECT 1 FROM message_parts pp
-                  WHERE pp.message_id = m.id AND pp.kind = 'tool_call')
-    THEN (SELECT jsonb_agg(p.payload ORDER BY p.sequence)
-            FROM message_parts p
-           WHERE p.message_id = m.id AND p.kind = 'tool_call' AND p.hidden_at IS NULL)
-    ELSE m.tool_calls
-  END AS tool_calls,
-  CASE
-    WHEN EXISTS (SELECT 1 FROM message_parts pp
-                  WHERE pp.message_id = m.id AND pp.kind = 'tool_result')
-    THEN (SELECT p.payload
-            FROM message_parts p
-           WHERE p.message_id = m.id AND p.kind = 'tool_result' AND p.hidden_at IS NULL
-           ORDER BY p.sequence LIMIT 1)
-    ELSE m.tool_results
-  END AS tool_results,
+  (SELECT jsonb_agg(p.payload ORDER BY p.sequence)
+     FROM message_parts p
+    WHERE p.message_id = m.id AND p.kind = 'tool_call' AND p.hidden_at IS NULL) AS tool_calls,
+  (SELECT p.payload
+     FROM message_parts p
+    WHERE p.message_id = m.id AND p.kind = 'tool_result' AND p.hidden_at IS NULL
+    ORDER BY p.sequence LIMIT 1) AS tool_results,
   (SELECT jsonb_agg(p.payload ORDER BY p.sequence)
      FROM message_parts p
     WHERE p.message_id = m.id AND p.kind = 'reasoning' AND p.hidden_at IS NULL) AS reasoning_parts
 FROM messages m;
 
+-- v1.13.20: drop legacy tool_calls/tool_results columns. Reads have routed
+-- through messages_with_parts since v1.13.1-B; dual-writes removed in this
+-- batch. The view above was simplified to remove COALESCE fallbacks before
+-- this drop (Postgres rejects column-drop on view-referenced columns).
+-- Idempotent via IF EXISTS.
+ALTER TABLE messages DROP COLUMN IF EXISTS tool_calls;
+ALTER TABLE messages DROP COLUMN IF EXISTS tool_results;
+
 -- v1.13.10: per-tool token cost rolling window. Derives from
 -- messages_with_parts (the v1.13.1-B view that COALESCEs message_parts over
 -- the legacy JSON column) so this works whether the chat predates v1.13.0
@@ -290,19 +283,6 @@ BEGIN
   END IF;
 END $$;
 
--- v1.12.1: drop stale inline CHECK constraints that were superseded by the
--- named *_chk variants above. messages_status_check missed 'cancelled' and
--- messages_role_check missed 'system' — both narrower than what's in use.
-DO $$
-BEGIN
-  IF EXISTS (SELECT 1 FROM pg_constraint WHERE conname = 'messages_status_check') THEN
-    ALTER TABLE messages DROP CONSTRAINT messages_status_check;
-  END IF;
-  IF EXISTS (SELECT 1 FROM pg_constraint WHERE conname = 'messages_role_check') THEN
-    ALTER TABLE messages DROP CONSTRAINT messages_role_check;
-  END IF;
-END $$;
-
 -- v1.2-project-ux: projects.status + projects.gitea_remote
 -- KEEP IN SYNC: apps/server/src/types/api.ts PROJECT_STATUSES
 ALTER TABLE projects ADD COLUMN IF NOT EXISTS status TEXT NOT NULL DEFAULT 'open';