feat: stack insights tables vertically and paginate Pull requests table (#24198)

The "By model" and "Pull requests" tables on the PR Insights page
(`/agents/settings/insights`) were side-by-side at `lg` breakpoints, and
the Pull requests table was hard-capped at 20 rows by the backend.

- Replaced `lg:grid-cols-2` with a single-column stacked layout so both
tables span the full content width.
- Removed the `LIMIT 20` from the `GetPRInsightsRecentPRs` SQL query so
all PRs in the selected time range are returned.
- Can add this back if we need it. If we do, we should add a little
subheader above this table to indicate that we're not showing all PRs
within the selected timeframe.
- Added client-side pagination to the Pull requests table using
`PaginationWidgetBase` (page size 10), matching the existing pattern in
`ChatCostSummaryView`.
- Renamed the section heading from "Recent" to "Pull requests" since it
now shows the full set for the time range.
<img width="1481" height="1817" alt="image"
src="https://github.com/user-attachments/assets/0066c42f-4d7b-4cee-b64b-6680848edc68"
/>


> 🤖 PR generated with Coder Agents

coderd/database/querier_test.go

@@ -10408,11 +10408,10 @@ func TestGetPRInsights(t *testing.T) {
 		assert.Equal(t, int64(1), summary.TotalPrsCreated)
 		assert.Equal(t, int64(8_000_000), summary.TotalCostMicros)
 
-		recent, err := store.GetPRInsightsRecentPRs(context.Background(), database.GetPRInsightsRecentPRsParams{
+		recent, err := store.GetPRInsightsPullRequests(context.Background(), database.GetPRInsightsPullRequestsParams{
 			StartDate: startDate,
 			EndDate:   endDate,
 			OwnerID:   noOwner,
-			LimitVal:  20,
 		})
 		require.NoError(t, err)
 		require.Len(t, recent, 1)
@@ -10442,11 +10441,10 @@ func TestGetPRInsights(t *testing.T) {
 		assert.Equal(t, int64(1), summary.TotalPrsMerged)
 
 		// RecentPRs ordered by created_at DESC: chatB is newer.
-		recent, err := store.GetPRInsightsRecentPRs(context.Background(), database.GetPRInsightsRecentPRsParams{
+		recent, err := store.GetPRInsightsPullRequests(context.Background(), database.GetPRInsightsPullRequestsParams{
 			StartDate: startDate,
 			EndDate:   endDate,
 			OwnerID:   noOwner,
-			LimitVal:  20,
 		})
 		require.NoError(t, err)
 		require.Len(t, recent, 2)
@@ -10491,11 +10489,10 @@ func TestGetPRInsights(t *testing.T) {
 		assert.Equal(t, int64(1), summary.TotalPrsCreated)
 		assert.Equal(t, int64(1), summary.TotalPrsMerged)
 
-		recent, err := store.GetPRInsightsRecentPRs(context.Background(), database.GetPRInsightsRecentPRsParams{
+		recent, err := store.GetPRInsightsPullRequests(context.Background(), database.GetPRInsightsPullRequestsParams{
 			StartDate: startDate,
 			EndDate:   endDate,
 			OwnerID:   noOwner,
-			LimitVal:  20,
 		})
 		require.NoError(t, err)
 		require.Len(t, recent, 1)
@@ -10533,11 +10530,10 @@ func TestGetPRInsights(t *testing.T) {
 		assert.Equal(t, int64(9_000_000), summary.TotalCostMicros)
 
 		// RecentPRs should return 1 row with the full tree cost.
-		recent, err := store.GetPRInsightsRecentPRs(context.Background(), database.GetPRInsightsRecentPRsParams{
+		recent, err := store.GetPRInsightsPullRequests(context.Background(), database.GetPRInsightsPullRequestsParams{
 			StartDate: startDate,
 			EndDate:   endDate,
 			OwnerID:   noOwner,
-			LimitVal:  20,
 		})
 		require.NoError(t, err)
 		require.Len(t, recent, 1)
@@ -10575,11 +10571,10 @@ func TestGetPRInsights(t *testing.T) {
 		assert.Equal(t, int64(2), summary.TotalPrsCreated)
 		assert.Equal(t, int64(8_000_000), summary.TotalCostMicros)
 
-		recent, err := store.GetPRInsightsRecentPRs(context.Background(), database.GetPRInsightsRecentPRsParams{
+		recent, err := store.GetPRInsightsPullRequests(context.Background(), database.GetPRInsightsPullRequestsParams{
 			StartDate: startDate,
 			EndDate:   endDate,
 			OwnerID:   noOwner,
-			LimitVal:  20,
 		})
 		require.NoError(t, err)
 		require.Len(t, recent, 2)
@@ -10621,11 +10616,10 @@ func TestGetPRInsights(t *testing.T) {
 		assert.Equal(t, int64(2), summary.TotalPrsCreated)
 		assert.Equal(t, int64(17_000_000), summary.TotalCostMicros)
 
-		recent, err := store.GetPRInsightsRecentPRs(context.Background(), database.GetPRInsightsRecentPRsParams{
+		recent, err := store.GetPRInsightsPullRequests(context.Background(), database.GetPRInsightsPullRequestsParams{
 			StartDate: startDate,
 			EndDate:   endDate,
 			OwnerID:   noOwner,
-			LimitVal:  20,
 		})
 		require.NoError(t, err)
 		require.Len(t, recent, 2)
@@ -10658,11 +10652,10 @@ func TestGetPRInsights(t *testing.T) {
 		assert.Equal(t, int64(2), summary.TotalPrsCreated)
 		assert.Equal(t, int64(10_000_000), summary.TotalCostMicros)
 
-		recent, err := store.GetPRInsightsRecentPRs(context.Background(), database.GetPRInsightsRecentPRsParams{
+		recent, err := store.GetPRInsightsPullRequests(context.Background(), database.GetPRInsightsPullRequestsParams{
 			StartDate: startDate,
 			EndDate:   endDate,
 			OwnerID:   noOwner,
-			LimitVal:  20,
 		})
 		require.NoError(t, err)
 		require.Len(t, recent, 2)
@@ -10695,11 +10688,10 @@ func TestGetPRInsights(t *testing.T) {
 		assert.Equal(t, int64(1), summary.TotalPrsCreated)
 		assert.Equal(t, int64(15_000_000), summary.TotalCostMicros)
 
-		recent, err := store.GetPRInsightsRecentPRs(context.Background(), database.GetPRInsightsRecentPRsParams{
+		recent, err := store.GetPRInsightsPullRequests(context.Background(), database.GetPRInsightsPullRequestsParams{
 			StartDate: startDate,
 			EndDate:   endDate,
 			OwnerID:   noOwner,
-			LimitVal:  20,
 		})
 		require.NoError(t, err)
 		require.Len(t, recent, 1)
@@ -10724,11 +10716,10 @@ func TestGetPRInsights(t *testing.T) {
 		assert.Equal(t, int64(1), summary.TotalPrsCreated)
 		assert.Equal(t, int64(0), summary.TotalCostMicros)
 
-		recent, err := store.GetPRInsightsRecentPRs(context.Background(), database.GetPRInsightsRecentPRsParams{
+		recent, err := store.GetPRInsightsPullRequests(context.Background(), database.GetPRInsightsPullRequestsParams{
 			StartDate: startDate,
 			EndDate:   endDate,
 			OwnerID:   noOwner,
-			LimitVal:  20,
 		})
 		require.NoError(t, err)
 		require.Len(t, recent, 1)
@@ -10767,11 +10758,10 @@ func TestGetPRInsights(t *testing.T) {
 		require.Len(t, byModel, 1)
 		assert.Equal(t, modelName, byModel[0].DisplayName)
 
-		recent, err := store.GetPRInsightsRecentPRs(context.Background(), database.GetPRInsightsRecentPRsParams{
+		recent, err := store.GetPRInsightsPullRequests(context.Background(), database.GetPRInsightsPullRequestsParams{
 			StartDate: startDate,
 			EndDate:   endDate,
 			OwnerID:   noOwner,
-			LimitVal:  20,
 		})
 		require.NoError(t, err)
 		require.Len(t, recent, 1)
@@ -10803,6 +10793,30 @@ func TestGetPRInsights(t *testing.T) {
 		assert.Equal(t, int64(8_000_000), summary.TotalCostMicros)
 		assert.Equal(t, int64(5_000_000), summary.MergedCostMicros)
 	})
+
+	t.Run("AllPRsReturnedWithSafetyCap", func(t *testing.T) {
+		t.Parallel()
+		store, userID, mcID := setupChatInfra(t)
+
+		// Create 25 distinct PRs — more than the old LIMIT 20 — and
+		// verify all are returned.
+		const prCount = 25
+		for i := range prCount {
+			chat := createChat(t, store, userID, mcID, fmt.Sprintf("chat-%d", i))
+			insertCostMessage(t, store, chat.ID, userID, mcID, 1_000_000)
+			linkPR(t, store, chat.ID,
+				fmt.Sprintf("https://github.com/org/repo/pull/%d", 100+i),
+				"merged", fmt.Sprintf("fix: pr-%d", i), 10, 2, 1)
+		}
+
+		recent, err := store.GetPRInsightsPullRequests(context.Background(), database.GetPRInsightsPullRequestsParams{
+			StartDate: startDate,
+			EndDate:   endDate,
+			OwnerID:   noOwner,
+		})
+		require.NoError(t, err)
+		assert.Len(t, recent, prCount, "all PRs within the date range should be returned")
+	})
 }
 
 func TestChatPinOrderQueries(t *testing.T) {