test(review): pin full-transcript history past 50 rows + changelog (PR #202)

Address the PR #202 review (approve-with-comments). The only actionable
non-blocking item was the test-coverage suggestion: the source switch in
AiChatService.handle from findRecent(chatId, ws, 50) to findAllByChat(chatId,
ws) was not pinned by a test. handle() is a streaming method the project marks
as not unit-testable, so cover the behavioral guarantee it now relies on at the
repo/integration level — seed a chat of 60 messages and assert the default
findAllByChat (exactly how handle calls it) returns the FULL transcript in
chronological order, including the first turn the old 50-window would have
dropped.

Also document the behavior change under CHANGELOG [Unreleased] -> Changed.

The two stability items (token-budget trim before streamText; O(N) history
rebuild per turn) are deferred: the reviewer flagged both as non-blocking
conscious trade-offs aligned with the PR's stated goal, and the trim is a
larger architecture change out of scope for this follow-up.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -55,6 +55,15 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- **AI chat now feeds the model the full stored transcript.** The per-turn model
+  conversation was rebuilt from a sliding window of the 50 most recent stored
+  rows, which silently dropped the beginning of any longer chat. It is now
+  rebuilt from the complete non-deleted transcript in chronological order, so
+  the model sees every turn (a 5000-row backstop guards process memory — a
+  safety net far above any realistic chat, not a conversational limit). On a
+  very long chat this can eventually reach the model's context window; the
+  client already surfaces that as "start a new chat". (#202)
+
 - **AI chat default provider is now `openai-compatible` (reasoning surfaced).**
   For the `openai` driver the chat provider defaults to the openai-compatible
   implementation, so a workspace pointing at z.ai/GLM/DeepSeek now streams the

apps/server/test/integration/ai-chat-message-status.int-spec.ts

@@ -267,4 +267,36 @@ describe('AiChatMessageRepo.update + sweepStreaming [integration]', () => {
     const all = await repo.findAllByChat(cappedChat, workspaceId, 100);
     expect(all.map((r) => r.content)).toEqual(['m1-oldest', 'm2', 'm3-newest']);
   });
+
+  it('default findAllByChat returns the FULL transcript past 50 rows — no recent-tail window (#202)', async () => {
+    // PR #202 swapped the model-history rebuild in AiChatService.handle from
+    // findRecent(chatId, ws, 50) to findAllByChat(chatId, ws) WITHOUT a limit
+    // arg. This pins the behavioral guarantee that switch relies on: a chat
+    // longer than the old 50-msg window comes back in FULL (oldest -> newest),
+    // so no early turns are silently dropped from what the model sees. The old
+    // 50-cap would have returned only the last 50 of these 60 rows.
+    const longChat = (
+      await createChat(db, { workspaceId, creatorId: userId })
+    ).id;
+    const base = Date.now();
+    const total = 60;
+    for (let i = 0; i < total; i++) {
+      await createMessage(db, {
+        workspaceId,
+        chatId: longChat,
+        content: `msg-${i}`,
+        // Strictly increasing timestamps so ordering is deterministic.
+        createdAt: new Date(base + i * 1000),
+      });
+    }
+
+    // Default args == exactly how handle() calls it now.
+    const history = await repo.findAllByChat(longChat, workspaceId);
+    expect(history).toHaveLength(total);
+    expect(history.map((r) => r.content)).toEqual(
+      Array.from({ length: total }, (_, i) => `msg-${i}`),
+    );
+    // The very first turn (which the old 50-window would have dropped) is present.
+    expect(history[0]!.content).toBe('msg-0');
+  });
 });