feat(tui): 30-day uptime timeline in inline detail panel

Statuspage-style colored bar — one █ per day, colored by uptime:
green (>= 99%), yellow (>= 95%), red (< 95%), gray (no data).
30-day percentage shown to the right.

Daily breakdown computed via ComputeDailyBreakdown from state_changes
and loaded alongside detail data in loadDetailCmd. Auto-updates on
cursor move.

internal/tui/messages.go

@@ -4,6 +4,7 @@ import (
 	"time"
 
 	"gitea.lerkolabs.com/lerkolabs/uptop/internal/models"
+	"gitea.lerkolabs.com/lerkolabs/uptop/internal/monitor"
 )
 
 // tabRefreshTTL bounds how often the DB-backed tab data (alerts, users, nodes,
@@ -34,8 +35,9 @@ type tabDataMsg struct {
 // on entry and refreshed on the tab-data cadence so View never touches the
 // database.
 type detailDataMsg struct {
-	siteID  int
-	changes []models.StateChange
+	siteID    int
+	changes   []models.StateChange
+	dailyDays []monitor.DayReport
 }
 
 // historyDataMsg carries the full state-change history for the history view.