[07/08] update draw/status surfaces for migrated graph and metadata caches

[mjc]

Stacked on mjc/gitoxide-spike-06-app-integration.

Why this PR exists:

• Earlier stack layers moved graph walking, query/action plumbing, and app state onto the new migrated data flow.
• This PR updates the rendering side so graph, status, statusbar, and related draw surfaces consume those migrated app/cache shapes efficiently.
• The main goal is to preserve the displayed UI while changing where draw code gets its data:
  • cached graph windows
  • graph projection cache
  • app-held worktree/head metadata
  • split uncommitted summary/detail state
  • path/lazy-repo app integration from the previous layer

What changed:

• Refactors graph drawing around explicit graph-window preparation and rendering.
• Changes draw_graph to accept Option<&git2::Repository> so the graph can still render cached/loading/empty states without forcing every path to have an eager repo handle.
• Uses GraphProjectionCache and GraphProjectionKey to avoid rebuilding message projection when the graph version, visible range, selected row, label toggles, uncommitted-row mode, and status counts have not changed.
• Splits graph rendering into smaller helpers for:
  • visible-window calculation
  • unborn/empty graph rendering
  • cached projection lookup
  • graph row widget construction
  • scrollbar rendering
  • search highlighting
• Refactors status-pane rendering around reusable row builders:
  • loading rows
  • empty rows
  • conflict rows
  • staged/unstaged file rows
  • selected-commit diff rows
• Adds explicit status-pane state handling for uncommitted summary vs uncommitted detail loading.
• Prevents unstaged detail rendering from pretending it is loaded before detail status has arrived.
• Rewrites statusbar rendering so it no longer needs to query a live repo during draw.
• Statusbar head/branch/detached state now comes from cached current worktree/head metadata.
• Statusbar branch/tag/stash/reflog counts now prefer cached graph pane windows when available.
• Reworks submodule stack display as spans instead of one preformatted label string.
• Keeps action-mode and zen-mode indicators in the statusbar, but builds them through helper iterators.
• Updates app draw dispatch so draw_statusbar no longer takes a repo argument.
• Updates inspector reflog rendering for the current cached reflog timestamp shape.
• Updates settings/graph/status/statusbar/title draw surfaces and tests for the migrated metadata shapes.
• Updates helper behavior:
  • symbol-theme loading no longer rewrites the symbol config just because it parsed successfully.
  • wrap_words avoids cloning when width is zero.
  • title rendering avoids an unnecessary file-name clone.

Algorithm difference:

• Graph drawing now separates “prepare visible window” from “render cached/projected rows.”
• Projection cache invalidation is explicit through GraphProjectionKey.
• Status rendering now builds a pane model first, then renders the pane from that model.
• Status empty/loading/selectable state is computed from BuiltStatusRows instead of scattered booleans.
• Statusbar rendering now uses app/cache state rather than issuing repo queries during draw.
• Display intent should remain equivalent:
  • same graph rows
  • same selected-row behavior
  • same search highlighting
  • same status icons/colors
  • same statusbar counts and mode indicators
  • same empty/loading states

Performance story:

• Improvements are in draw-path recomputation.
• Graph message projection can be reused when the graph projection key has not changed.
• Statusbar avoids repo lookups during draw.
• Status panes reuse shared row-building paths instead of rebuilding the same logic in multiple branches.

Benchmark Results for this PR

Command shape: hyperfine --warmup 5 './target/release/guitar /home/mjc/src/linux --exit-when-graph-complete'.

CPU: M1 MacBook Pro 16GB

Ref	Total	vs main	User	System	CPU
07-draw-status	1.618s	97.21x	1.36s	0.08s	89%

CPU: 5950x Linux/ZFS

Ref	Total	vs main	User	System	CPU
07-draw-status	1.632s	60.81x	1.34s	0.18s	93%

Memory: 5950x Linux/ZFS

Ref	Peak heap	Peak RSS
07-draw-status	419.89M	916.59M

Top 10 heaptrack allocation sites for `07-draw-status`

1. 29430 calls, 1.61M peak - <>::finish_grow
2. 17060 calls, 0B peak - gix_ref::raw::convert::<>::from
3. 17060 calls, 878.18K peak - guitar::core::walker::Walker::new
4. 12342 calls, 0B peak - <>::push_back_tracked_path_component
5. 10240 calls, 154.43M peak - alloc::raw_vec::RawVecInner<>::finish_grow
6. 9776 calls, 7.47K peak - gix_config::parse::event::<>::to_owned
7. 2816 calls, 519B peak - gix_config::file::util::<>::push_section_internal
8. 1308 calls, 0B peak - gix_index::extension::tree::decode::one_recursive
9. 902 calls, 99B peak - facet_core::impls::alloc::string::<>::SHAPE::{{constant}}::VTABLE::parse
10. 778 calls, 0B peak - facet_reflect::partial::partial_api::lists::<>::begin_list_item

[Copilot]

Copilot wasn't able to review this pull request because it exceeds the maximum number of lines (20,000). Try reducing the number of changed lines and requesting a review from Copilot again.