refactor: prune session-store and agent-list dead code

The session_entries supersede pipeline was a design that never
shipped: `SqliteSessionStore.replaceMessages` / `appendCompaction`,
`sessionEntries.replace` / `listAll` / `deleteForSession`, and the
`"compaction" | "summary"` kind variants had zero live callers.
Compaction wires through pi's `transformContext` and leaves the
persisted transcript alone, so the shadow-row machinery was pure
cruft with two tests propping it up.

Rip it out: the store exposes only `loadMessages` and
`appendMessage`, `sessionEntries` exposes only `append` and
`listActive`, and `SessionEntryKind` narrows to `"message"` so new
writers can't re-introduce a dead kind by accident.
`is_superseded` stays on the table — the DB column is harmless
with no writer, and dropping it is a separate schema migration
concern.

`listTopLevelAgentIds` loses its only caller in the previous
commit (company channel now fans out through
`listCompanyBroadcastAgentIds`), so it goes too. Three tests that
validated the removed behaviour are deleted; the one remaining
session-store test still covers the live `append + load` path.

src/main/agent-runtime/sqlite-session-store.ts

@@ -4,9 +4,12 @@ import type { AppDatabase } from "@main/database";
 /**
  * SQLite-backed pi `AgentMessage[]` store.
  *
- * One store instance per task_session. Owners must call `appendMessage`
- * exactly once per pi `message_end` event, and `replaceMessages` after pi
- * `compact` returns a compacted message list.
+ * One store instance per task_session. `appendMessage` runs exactly
+ * once per pi `message_end` event; `loadMessages` reads the live
+ * transcript back at `prepareRun`. Compaction happens at LLM-call
+ * time via pi's `transformContext` hook and does not rewrite the
+ * persisted transcript — the session shadow is the durable truth,
+ * the compacted payload is a per-call view.
  */
 export class SqliteSessionStore {
   constructor(
@@ -33,28 +36,4 @@ export class SqliteSessionStore {
       payloadJson: JSON.stringify(message),
     });
   }
-
-  appendCompaction(summary: string): void {
-    this.db.sessionEntries.append({
-      taskSessionId: this.taskSessionId,
-      kind: "compaction",
-      role: null,
-      payloadJson: JSON.stringify({ summary }),
-    });
-  }
-
-  replaceMessages(messages: AgentMessage[], compactionSummary?: string): void {
-    const entries: Array<{ kind: "message" | "compaction"; role: string | null; payloadJson: string }> = [];
-    if (compactionSummary) {
-      entries.push({ kind: "compaction", role: null, payloadJson: JSON.stringify({ summary: compactionSummary }) });
-    }
-    for (const message of messages) {
-      entries.push({
-        kind: "message",
-        role: (message as { role?: string }).role ?? null,
-        payloadJson: JSON.stringify(message),
-      });
-    }
-    this.db.sessionEntries.replace({ taskSessionId: this.taskSessionId, entries });
-  }
 }

src/main/database-base.ts

@@ -252,7 +252,6 @@ export class AppDatabaseBase {
   setHeartbeatPolicy(agentId: string, companyId: string, policy: { enabled?: boolean; intervalSec?: number; cooldownSec?: number; maxConcurrentRuns?: number; wakeOnDemand?: boolean }) { return this.agents.setHeartbeatPolicy(agentId, companyId, policy); }
   countActiveRunsForAgent(agentId: string, companyId: string) { return this.agents.countActiveRunsForAgent(agentId, companyId); }
   listDepartmentAgentIds(companyId: string, department: string) { return this.agents.listDepartmentAgentIds(companyId, department); }
-  listTopLevelAgentIds(companyId: string) { return this.agents.listTopLevelAgentIds(companyId); }
   listCompanyBroadcastAgentIds(companyId: string) { return this.agents.listCompanyBroadcastAgentIds(companyId); }
   listIncidentPingableAgentIds(companyId: string) { return this.agents.listIncidentPingableAgentIds(companyId); }
   findAgentName(agentId: string) { return this.agents.findAgentName(agentId); }

src/main/database/agents-hierarchy.ts

@@ -284,18 +284,6 @@ export function buildAgentHierarchyMethods(
       ).map((row) => row.id);
     },
 
-    /**
-     * Returns ids of non-terminated agents that have no manager (top of the
-     * reporting tree). Used for board-only fan-outs where only top-level
-     * leadership should be notified.
-     */
-    listTopLevelAgentIds(companyId: string): string[] {
-      return readAll<{ id: string }>(
-        "select id from agents where company_id = ? and reports_to is null and status != 'terminated'",
-        companyId,
-      ).map((row) => row.id);
-    },
-
     /**
      * Returns ids of every agent that is eligible to receive a routine
      * company-wide broadcast. Paused, pending-approval, and terminated

src/main/database/session-entries.ts

@@ -3,7 +3,15 @@ import type { DatabaseSync } from "node:sqlite";
 import type { ReadAll, Transaction } from "./helpers";
 import { nowIso } from "./helpers";
 
-export type SessionEntryKind = "message" | "compaction" | "summary";
+/**
+ * The `session_entries` table only ever stores one kind — full pi
+ * `AgentMessage` envelopes emitted by `message_end`. Earlier builds
+ * reserved `"compaction"` and `"summary"` variants for a supersede
+ * pipeline that never shipped; their writers are gone and the column
+ * holds `"message"` for every live row. Narrowing the type prevents
+ * new code from writing a dead kind by accident.
+ */
+export type SessionEntryKind = "message";
 
 export interface SessionEntryRow {
   id: string;
@@ -12,7 +20,6 @@ export interface SessionEntryRow {
   kind: SessionEntryKind;
   role: string | null;
   payloadJson: string;
-  isSuperseded: boolean;
   createdAt: string;
 }
 
@@ -23,15 +30,10 @@ export interface AppendInput {
   payloadJson: string;
 }
 
-export interface ReplaceInput {
-  taskSessionId: string;
-  entries: Array<{ kind: SessionEntryKind; role?: string | null; payloadJson: string }>;
-}
-
 export function buildSessionEntryMethods(
   getDb: () => DatabaseSync,
   readAll: ReadAll,
-  transaction: Transaction,
+  _transaction: Transaction,
 ) {
   function nextSequence(taskSessionId: string): number {
     const rows = readAll<{ maxSeq: number | null }>(
@@ -66,7 +68,6 @@ export function buildSessionEntryMethods(
       kind: input.kind,
       role: input.role ?? null,
       payloadJson: input.payloadJson,
-      isSuperseded: false,
       createdAt: created,
     };
   }
@@ -79,10 +80,9 @@ export function buildSessionEntryMethods(
       kind: SessionEntryKind;
       role: string | null;
       payload_json: string;
-      is_superseded: number;
       created_at: string;
     }>(
-      "select id, task_session_id, sequence, kind, role, payload_json, is_superseded, created_at from session_entries where task_session_id = ? and is_superseded = 0 order by created_at asc, sequence asc",
+      "select id, task_session_id, sequence, kind, role, payload_json, created_at from session_entries where task_session_id = ? and is_superseded = 0 order by created_at asc, sequence asc",
       taskSessionId,
     );
     return rows.map((row) => ({
@@ -92,62 +92,9 @@ export function buildSessionEntryMethods(
       kind: row.kind,
       role: row.role,
       payloadJson: row.payload_json,
-      isSuperseded: false,
       createdAt: row.created_at,
     }));
   }
 
-  function listAll(taskSessionId: string): SessionEntryRow[] {
-    const rows = readAll<{
-      id: string;
-      task_session_id: string;
-      sequence: number;
-      kind: SessionEntryKind;
-      role: string | null;
-      payload_json: string;
-      is_superseded: number;
-      created_at: string;
-    }>(
-      "select id, task_session_id, sequence, kind, role, payload_json, is_superseded, created_at from session_entries where task_session_id = ? order by sequence asc",
-      taskSessionId,
-    );
-    return rows.map((row) => ({
-      id: row.id,
-      taskSessionId: row.task_session_id,
-      sequence: row.sequence,
-      kind: row.kind,
-      role: row.role,
-      payloadJson: row.payload_json,
-      isSuperseded: row.is_superseded === 1,
-      createdAt: row.created_at,
-    }));
-  }
-
-  function replace(input: ReplaceInput): SessionEntryRow[] {
-    return transaction(() => {
-      getDb()
-        .prepare("update session_entries set is_superseded = 1 where task_session_id = ? and is_superseded = 0")
-        .run(input.taskSessionId);
-      const inserted: SessionEntryRow[] = [];
-      for (const entry of input.entries) {
-        inserted.push(
-          append({
-            taskSessionId: input.taskSessionId,
-            kind: entry.kind,
-            role: entry.role ?? null,
-            payloadJson: entry.payloadJson,
-          }),
-        );
-      }
-      return inserted;
-    });
-  }
-
-  function deleteForSession(taskSessionId: string): void {
-    getDb()
-      .prepare("delete from session_entries where task_session_id = ?")
-      .run(taskSessionId);
-  }
-
-  return { append, listActive, listAll, replace, deleteForSession };
+  return { append, listActive };
 }

tests/integration/pi-mono-migrations.spec.ts

@@ -101,38 +101,6 @@ describe("pi-mono migrations 27 + 28", () => {
     dbB.close();
   });
 
-  it("session_entries respects the unique (task_session_id, sequence) index across replace cycles", async () => {
-    const dir = await freshProfile("agentcompany-migration-replace-");
-    const db = new AppDatabase(dir);
-    db.init();
-
-    for (let i = 0; i < 3; i += 1) {
-      db.sessionEntries.append({
-        taskSessionId: "replace-test",
-        kind: "message",
-        role: "user",
-        payloadJson: JSON.stringify({ role: "user", content: `t${i}` }),
-      });
-    }
-    db.sessionEntries.replace({
-      taskSessionId: "replace-test",
-      entries: [
-        { kind: "compaction", role: null, payloadJson: JSON.stringify({ summary: "summarised" }) },
-        { kind: "message", role: "user", payloadJson: JSON.stringify({ role: "user", content: "post" }) },
-      ],
-    });
-
-    const active = db.sessionEntries.listActive("replace-test");
-    expect(active).toHaveLength(2);
-    expect(active[0]?.kind).toBe("compaction");
-    expect(active[1]?.kind).toBe("message");
-
-    const all = db.sessionEntries.listAll("replace-test");
-    expect(all.length).toBe(5);
-    expect(all.filter((row) => row.isSuperseded).length).toBe(3);
-    db.close();
-  });
-
   it("seedConnectors prunes legacy connector rows and inserts the full pi-mono + Fireworks catalog", async () => {
     const dir = await freshProfile("agentcompany-migration-seed-");
     const db = new AppDatabase(dir);

tests/unit/sqlite-session-store.test.ts

@@ -8,7 +8,7 @@ import { SqliteSessionStore } from "../../src/main/agent-runtime/sqlite-session-
 
 /**
  * Verifies the SqliteSessionStore round-trips pi `AgentMessage` values
- * correctly through the new `session_entries` table (migration 27).
+ * correctly through the `session_entries` table.
  */
 describe("SqliteSessionStore", () => {
   let tempDir: string;
@@ -49,32 +49,4 @@ describe("SqliteSessionStore", () => {
     expect((loaded[0] as { role: string }).role).toBe("user");
     expect((loaded[1] as { role: string }).role).toBe("assistant");
   });
-
-  it("appends a compaction marker that does not appear as a message", () => {
-    const store = new SqliteSessionStore(db, TASK_SESSION_ID);
-    store.appendMessage({ role: "user", content: [{ type: "text", text: "first" }], timestamp: Date.now() } as AgentMessage);
-    store.appendCompaction("Earlier conversation summarised: planning phase complete.");
-    const loaded = store.loadMessages();
-    expect(loaded).toHaveLength(1);
-  });
-
-  it("replaceMessages supersedes prior rows and inserts new ones in order", () => {
-    const store = new SqliteSessionStore(db, TASK_SESSION_ID);
-    store.appendMessage({ role: "user", content: [{ type: "text", text: "old-1" }], timestamp: Date.now() } as AgentMessage);
-    store.appendMessage({ role: "assistant", content: [{ type: "text", text: "old-2" }], timestamp: Date.now() } as AgentMessage);
-
-    const compacted: AgentMessage[] = [
-      { role: "user", content: [{ type: "text", text: "context summary" }], timestamp: Date.now() } as AgentMessage,
-    ];
-    store.replaceMessages(compacted, "Summary of prior turns.");
-
-    const active = store.loadMessages();
-    expect(active).toHaveLength(1);
-    expect((active[0] as { content: { text: string }[] }).content[0]?.text).toBe("context summary");
-
-    // Check: pre-replace messages must still exist as superseded audit rows.
-    const all = db.sessionEntries.listAll(TASK_SESSION_ID);
-    const supersededCount = all.filter((row) => row.isSuperseded).length;
-    expect(supersededCount).toBe(2);
-  });
 });