fix: center viewport on search match navigation

Use centerViewportOnCursor instead of syncViewportToCursor for search
navigation to match hunk navigation behavior. Update CLAUDE.md with
session learnings.

Author: umputun

CLAUDE.md

@@ -73,3 +73,6 @@ git diff → diff.ParseUnifiedDiff() → []DiffLine
 - Tab replacement happens at render time in `renderDiffLine`, not in diff parsing
 - `run()` resolves git repo root via `git rev-parse --show-toplevel` so revdiff works from any subdirectory
 - Help overlay uses `overlayCenter()` (ANSI-aware compositing via `charmbracelet/x/ansi.Cut`) to render on top of existing content; background (tree pane) remains visible at the edges
+- **ANSI nesting with lipgloss**: `lipgloss.Render()` emits `\033[0m` (full reset) which breaks outer style backgrounds. For styled substrings inside a lipgloss container (status bar separators, search highlights), use raw ANSI sequences via `ansiColor(hex, code)` — code 38 for fg, 48 for bg. Never use `lipgloss.NewStyle().Render()` for inline elements within a lipgloss-rendered parent.
+- Status bar mode icons (`▼ ◉ ↩ ≋`) are always rendered on the right side via `statusModeIcons()`. Active modes use `StatusFg`, inactive use `Muted` — both via raw ANSI fg sequences. Graceful degradation on narrow terminals drops left segments: search position first (`statusSegmentsNoSearch`), then hunk info (`statusSegmentsMinimal`), then truncates filename.
+- Search and hunk navigation both use `centerViewportOnCursor()` to center the target in the middle of the viewport. Use `syncViewportToCursor()` only for cursor movements that should keep the cursor barely visible (j/k scrolling).

ui/search.go

@@ -56,7 +56,7 @@ func (m *Model) submitSearch() {
 		m.searchCursor = i
 		m.diffCursor = idx
 		m.cursorOnAnnotation = false
-		m.syncViewportToCursor()
+		m.centerViewportOnCursor()
 		return
 	}
 
@@ -68,7 +68,7 @@ func (m *Model) submitSearch() {
 		m.searchCursor = i
 		m.diffCursor = idx
 		m.cursorOnAnnotation = false
-		m.syncViewportToCursor()
+		m.centerViewportOnCursor()
 		return
 	}
 }
@@ -92,7 +92,7 @@ func (m *Model) nextSearchMatch() {
 	}
 	m.diffCursor = m.searchMatches[m.searchCursor]
 	m.cursorOnAnnotation = false
-	m.syncViewportToCursor()
+	m.centerViewportOnCursor()
 }
 
 // prevSearchMatch moves to the previous search match with wrap-around.
@@ -117,7 +117,7 @@ func (m *Model) prevSearchMatch() {
 	}
 	m.diffCursor = m.searchMatches[m.searchCursor]
 	m.cursorOnAnnotation = false
-	m.syncViewportToCursor()
+	m.centerViewportOnCursor()
 }
 
 // cancelSearch exits searching mode without submitting.