refactor(session): nuke dead sessionParams / sessionDisplayId pipeline (v43)

These columns and the messages that plumbed them existed for the CLI-
adapter era — Gemini's resume id and provider-specific session params
rode the run-finished envelope back onto the session row so the next
turn could resume. Pi Mono dispatches every provider through pi-ai and
emits neither value. The worker has been posting literal null on every
finish, finalizeRun has been writing null into task_sessions, and
rotateSession has been carrying null forward.

Remove the wire, the writer, the carry-forward, and the columns:

  - v43 migration rebuilds task_sessions without session_params_json /
    session_display_id, and runs without session_display_id. Follows
    the idempotent "create new, copy, swap, reindex" pattern used by
    v41. context_snapshot_json is preserved (also unreferenced today
    but outside this cleanup's scope).
  - RunJob / EnqueueRunPayload / ChildMessage / worker-types zod
    schema no longer carry the fields. finishRun() / createNewSession()
    signatures tighten in lockstep.
  - rotateSession starts the new session with fresh counters and no
    carry-forward.
  - turn-context resolveSession returns just the session id.
  - TaskSessionRecord / RunRecord lose the dead fields.

498/498 unit tests pass. typecheck + build clean.

tests/unit/atomic-checkout.test.ts

@@ -196,7 +196,6 @@ describe("CAS checkout", () => {
       exitCode: 0,
       signal: null,
       model: null,
-      sessionDisplayId: null,
       unattributedCost: false,
     });
 
@@ -337,7 +336,6 @@ describe("CAS checkout", () => {
       exitCode: null,
       signal: null,
       model: null,
-      sessionDisplayId: null,
       unattributedCost: true,
     });
 
@@ -382,7 +380,6 @@ describe("CAS checkout", () => {
       exitCode: null,
       signal: null,
       model: null,
-      sessionDisplayId: null,
       unattributedCost: true,
     });
 
@@ -417,7 +414,6 @@ describe("CAS checkout", () => {
       exitCode: 1,
       signal: null,
       model: null,
-      sessionDisplayId: null,
       unattributedCost: false,
     });
 

tests/unit/dashboard-charts.test.ts

@@ -27,7 +27,6 @@ function makeRun(overrides: Partial<RunRecord> = {}): RunRecord {
     exitCode: null,
     signal: null,
     model: null,
-    sessionDisplayId: null,
     costUsd: null,
     unattributedCost: false,
     startedAt: null,

tests/unit/database.test.ts

@@ -296,7 +296,6 @@ describe("AppDatabase", () => {
       exitCode: 0,
       signal: null,
       model: "gpt-5",
-      sessionDisplayId: "session-budget",
       unattributedCost: false,
     });
 
@@ -515,7 +514,6 @@ describe("AppDatabase", () => {
       exitCode: 0,
       signal: null,
       model: null,
-      sessionDisplayId: null,
       unattributedCost: true,
     });
 

tests/unit/edge-case-budget.test.ts

@@ -167,7 +167,6 @@ describe("Edge Case: Budget Exhaustion Mid-Run (D-05.2)", () => {
       exitCode: 0,
       signal: null,
       model: "gemini-pro",
-      sessionDisplayId: null,
       unattributedCost: false,
     });
 
@@ -182,7 +181,6 @@ describe("Edge Case: Budget Exhaustion Mid-Run (D-05.2)", () => {
       exitCode: 0,
       signal: null,
       model: "gemini-pro",
-      sessionDisplayId: null,
       unattributedCost: false,
     });
 
@@ -234,7 +232,6 @@ describe("Edge Case: Budget Exhaustion Mid-Run (D-05.2)", () => {
       exitCode: 0,
       signal: null,
       model: "gemini-pro",
-      sessionDisplayId: null,
       unattributedCost: false,
     });
 
@@ -283,7 +280,6 @@ describe("Edge Case: Budget Exhaustion Mid-Run (D-05.2)", () => {
       exitCode: 0,
       signal: null,
       model: "gemini-pro",
-      sessionDisplayId: null,
       unattributedCost: false,
     });
 
@@ -341,7 +337,6 @@ describe("Edge Case: Budget Exhaustion Mid-Run (D-05.2)", () => {
       exitCode: 0,
       signal: null,
       model: "gemini-pro",
-      sessionDisplayId: null,
       unattributedCost: false,
     });
 
@@ -394,7 +389,6 @@ describe("Edge Case: Budget Exhaustion Mid-Run (D-05.2)", () => {
       exitCode: 0,
       signal: null,
       model: "gemini-pro",
-      sessionDisplayId: null,
       unattributedCost: false,
     });
 
@@ -443,7 +437,6 @@ describe("Edge Case: Budget Exhaustion Mid-Run (D-05.2)", () => {
       exitCode: 0,
       signal: null,
       model: "gemini-pro",
-      sessionDisplayId: null,
       unattributedCost: false,
     });
 

tests/unit/edge-case-session.test.ts

@@ -118,8 +118,6 @@ describe("Edge Case: Session Rotation During Execution (D-05.3)", () => {
       companyId,
       agentId,
       adapterType: "gemini-cli",
-      sessionParamsJson: null,
-      sessionDisplayId: null,
     });
 
     // Simulate runs until we reach the maxRuns threshold (20)
@@ -146,8 +144,6 @@ describe("Edge Case: Session Rotation During Execution (D-05.3)", () => {
       companyId,
       agentId,
       adapterType: "gemini-cli",
-      sessionParamsJson: null,
-      sessionDisplayId: null,
     });
 
     // Accumulate tokens past the threshold in one big call
@@ -172,8 +168,6 @@ describe("Edge Case: Session Rotation During Execution (D-05.3)", () => {
       companyId,
       agentId,
       adapterType: "gemini-cli",
-      sessionParamsJson: null,
-      sessionDisplayId: null,
     });
 
     // Accumulate enough to trigger rotation
@@ -197,7 +191,6 @@ describe("Edge Case: Session Rotation During Execution (D-05.3)", () => {
       exitCode: 0,
       signal: null,
       model: "gemini-pro",
-      sessionDisplayId: null,
       unattributedCost: false,
     });
 
@@ -229,8 +222,6 @@ describe("Edge Case: Session Rotation During Execution (D-05.3)", () => {
       companyId,
       agentId,
       adapterType: "gemini-cli",
-      sessionParamsJson: JSON.stringify({ resumeKey: "abc" }),
-      sessionDisplayId: "gemini-session-1",
     });
 
     // Add usage to the old session
@@ -244,8 +235,6 @@ describe("Edge Case: Session Rotation During Execution (D-05.3)", () => {
       companyId,
       agentId,
       adapterType: "gemini-cli",
-      sessionParamsJson: JSON.stringify({ resumeKey: "abc" }),
-      sessionDisplayId: "gemini-session-2",
     });
 
     // Get the new active session
@@ -268,8 +257,6 @@ describe("Edge Case: Session Rotation During Execution (D-05.3)", () => {
       companyId,
       agentId,
       adapterType: "claude-pro",
-      sessionParamsJson: null,
-      sessionDisplayId: null,
     });
 
     // Accumulate way past all thresholds
@@ -292,8 +279,6 @@ describe("Edge Case: Session Rotation During Execution (D-05.3)", () => {
       companyId,
       agentId,
       adapterType: "openai-codex",
-      sessionParamsJson: null,
-      sessionDisplayId: null,
     });
 
     // Accumulate way past all thresholds
@@ -317,8 +302,6 @@ describe("Edge Case: Session Rotation During Execution (D-05.3)", () => {
       companyId,
       agentId,
       adapterType: "gemini-cli",
-      sessionParamsJson: null,
-      sessionDisplayId: null,
     });
     db.incrementSessionUsage(sessionId, 300000, 200000, "run-1");
 
@@ -338,7 +321,6 @@ describe("Edge Case: Session Rotation During Execution (D-05.3)", () => {
       exitCode: 0,
       signal: null,
       model: "gemini-pro",
-      sessionDisplayId: null,
       unattributedCost: false,
     });
 

tests/unit/session-management.test.ts

@@ -106,8 +106,6 @@ describe("task_sessions CRUD", () => {
       companyId,
       agentId,
       adapterType: "claude-pro",
-      sessionParamsJson: JSON.stringify({ sessionId: "abc123" }),
-      sessionDisplayId: "claude-abc123",
     });
 
     const session = db.getSessionById(sessionId);
@@ -116,8 +114,6 @@ describe("task_sessions CRUD", () => {
     expect(session!.companyId).toBe(companyId);
     expect(session!.agentId).toBe(agentId);
     expect(session!.adapterType).toBe("claude-pro");
-    expect(session!.sessionParamsJson).toBe(JSON.stringify({ sessionId: "abc123" }));
-    expect(session!.sessionDisplayId).toBe("claude-abc123");
     expect(session!.runCount).toBe(0);
     expect(session!.totalInputTokens).toBe(0);
     expect(session!.totalOutputTokens).toBe(0);
@@ -132,8 +128,6 @@ describe("task_sessions CRUD", () => {
       companyId,
       agentId,
       adapterType: "claude-pro",
-      sessionParamsJson: null,
-      sessionDisplayId: null,
     });
 
     db.incrementSessionUsage(sessionId, 1000, 500, "run-001");
@@ -159,8 +153,6 @@ describe("task_sessions CRUD", () => {
       companyId,
       agentId,
       adapterType: "claude-pro",
-      sessionParamsJson: null,
-      sessionDisplayId: null,
     });
 
     db.archiveSession(sessionId, "max_runs", "# Handoff\nSession reached 20 runs.");
@@ -178,8 +170,6 @@ describe("task_sessions CRUD", () => {
       companyId,
       agentId,
       adapterType: "gemini-cli",
-      sessionParamsJson: JSON.stringify({ key: "val" }),
-      sessionDisplayId: "gemini-session-1",
     });
 
     expect(typeof sessionId).toBe("string");
@@ -204,7 +194,6 @@ describe("task_sessions CRUD", () => {
       exitCode: 0,
       signal: null,
       model: "claude-4-opus",
-      sessionDisplayId: null,
       unattributedCost: false,
     });
 
@@ -217,7 +206,6 @@ describe("task_sessions CRUD", () => {
       exitCode: 1,
       signal: null,
       model: "claude-4-opus",
-      sessionDisplayId: null,
       unattributedCost: false,
     });
 
@@ -292,8 +280,6 @@ describe("session management service", () => {
         companyId: "co-1",
         agentId: "agent-1",
         adapterType: "gemini-cli",
-        sessionParamsJson: null,
-        sessionDisplayId: null,
         lastRunId: null,
         lastError: null,
         runCount: 5,
@@ -317,8 +303,6 @@ describe("session management service", () => {
         companyId: "co-1",
         agentId: "agent-1",
         adapterType: "gemini-cli",
-        sessionParamsJson: null,
-        sessionDisplayId: null,
         lastRunId: null,
         lastError: null,
         runCount: 20,
@@ -342,8 +326,6 @@ describe("session management service", () => {
         companyId: "co-1",
         agentId: "agent-1",
         adapterType: "gemini-cli",
-        sessionParamsJson: null,
-        sessionDisplayId: null,
         lastRunId: null,
         lastError: null,
         runCount: 3,
@@ -368,8 +350,6 @@ describe("session management service", () => {
         companyId: "co-1",
         agentId: "agent-1",
         adapterType: "gemini-cli",
-        sessionParamsJson: null,
-        sessionDisplayId: null,
         lastRunId: null,
         lastError: null,
         runCount: 1,
@@ -398,8 +378,6 @@ describe("session management service", () => {
         companyId: "co-1",
         agentId: "agent-1",
         adapterType: "claude-pro",
-        sessionParamsJson: null,
-        sessionDisplayId: null,
         lastRunId: null,
         lastError: null,
         runCount: 100, // Way over threshold
@@ -428,8 +406,6 @@ describe("session management service", () => {
         companyId: "co-1",
         agentId: "agent-1",
         adapterType: "gemini-cli",
-        sessionParamsJson: null,
-        sessionDisplayId: null,
         lastRunId: null,
         lastError: null,
         runCount: 5,
@@ -453,8 +429,6 @@ describe("session management service", () => {
         companyId: "co-1",
         agentId: "agent-1",
         adapterType: "gemini-cli",
-        sessionParamsJson: null,
-        sessionDisplayId: null,
         lastRunId: null,
         lastError: null,
         runCount: 10, // Below default 20
@@ -478,8 +452,6 @@ describe("session management service", () => {
         companyId: "co-1",
         agentId: "agent-1",
         adapterType: "gemini-cli",
-        sessionParamsJson: null,
-        sessionDisplayId: null,
         lastRunId: null,
         lastError: null,
         runCount: 19, // Just below default 20
@@ -512,8 +484,6 @@ describe("session management service", () => {
         companyId,
         agentId,
         adapterType: "claude-pro",
-        sessionParamsJson: null,
-        sessionDisplayId: null,
       });
       const svc = createSessionManagementService({ db, logger: mockLogger });
 
@@ -537,8 +507,6 @@ describe("session management service", () => {
         companyId,
         agentId,
         adapterType: "gemini-cli",
-        sessionParamsJson: null,
-        sessionDisplayId: null,
       });
 
       // Create a completed run for history
@@ -551,7 +519,6 @@ describe("session management service", () => {
         exitCode: 0,
         signal: null,
         model: "gemini-pro",
-        sessionDisplayId: null,
         unattributedCost: false,
       });
 
@@ -584,8 +551,6 @@ describe("session management service", () => {
         companyId,
         agentId,
         adapterType: "gemini-cli",
-        sessionParamsJson: JSON.stringify({ resumeId: "old-abc" }),
-        sessionDisplayId: "gemini-old",
       });
 
       // Add some usage
@@ -606,14 +571,12 @@ describe("session management service", () => {
       expect(archivedRows[0].rotationReason).toBe("threshold_exceeded");
       expect(archivedRows[0].handoffMarkdown).toContain("# Session Handoff");
 
-      // New session is a distinct row, with fresh counters and copied params
+      // New session is a distinct row with fresh counters.
       const newSession = db.getSessionById(newSessionId)!;
       expect(newSession.id).toBe(newSessionId);
       expect(newSession.runCount).toBe(0);
       expect(newSession.totalInputTokens).toBe(0);
       expect(newSession.totalOutputTokens).toBe(0);
-      expect(newSession.sessionParamsJson).toBe(JSON.stringify({ resumeId: "old-abc" }));
-      expect(newSession.sessionDisplayId).toBe("gemini-old");
     });
   });
 
@@ -630,8 +593,6 @@ describe("session management service", () => {
         companyId,
         agentId,
         adapterType: "gemini-cli",
-        sessionParamsJson: null,
-        sessionDisplayId: null,
       });
       db.incrementSessionUsage(session1Id, 100000, 50000, "run-1");
       const session1 = db.getSessionById(session1Id)!;
@@ -648,8 +609,6 @@ describe("session management service", () => {
         companyId,
         agentId,
         adapterType: "gemini-cli",
-        sessionParamsJson: null,
-        sessionDisplayId: null,
       });
       const svc = createSessionManagementService({ db, logger: mockLogger });
 
@@ -668,8 +627,6 @@ describe("session management service", () => {
         companyId,
         agentId,
         adapterType: "gemini-cli",
-        sessionParamsJson: null,
-        sessionDisplayId: null,
       });
 
       // Pre-populate some usage

tests/unit/store.test.ts

@@ -270,7 +270,6 @@ const fakeTask = (id: string, title = "Task"): TaskRecord => ({
   priority: "medium",
   activeRunId: null,
   sessionJson: null,
-  sessionDisplayId: null,
   requiresUserReview: false,
   startedAt: null,
   completedAt: null,
@@ -292,7 +291,6 @@ const fakeRun = (id: string): RunRecord => ({
   exitCode: null,
   signal: null,
   model: null,
-  sessionDisplayId: null,
   unattributedCost: false,
   startedAt: null,
   finishedAt: null,