perf(ui): use ListView.separated for lazy horizontal breadcrumb rendering

[danteboe]

Motivation

• Previous SingleChildScrollView + Row eagerly built all breadcrumb items causing poor performance in deep trees.

What changed

• Replaced with ListView.separated horizontal builder keyed by ValueKey(view.id) and lazy separator builder. Items build on demand.

Performance impact

• Converts eager construction to on-demand builders, significantly reducing initial layout cost and memory pressure.

Testing

• Manual navigation across deep breadcrumb stacks to confirm rendering and scrolling.

Risk and compatibility

• Low. Visual parity kept; separators preserved.

Checklist

• flutter analyze
• Reviewer: frontend/ui

Summary by Sourcery

Optimize breadcrumb rendering performance and logging/serialization efficiency across Flutter UI and Rust backends, while updating commit lint configuration and cleaning up unused files.

Bug Fixes:

• Ensure view rename popover has a valid, up-to-date state when opened from the title bar.

Enhancements:

• Refactor the Flutter view title bar to use a stateful widget with cached breadcrumb widgets and a horizontally scrolling ListView for lazy breadcrumb rendering.
• Improve ViewTitle popover construction by reusing the latest bloc state and extracting a dedicated builder for the rename popover.
• Optimize Rust logging by reusing a thread-local buffer for JSON serialization of spans and events to reduce allocations.
• Avoid intermediate allocations when serializing chat RAG IDs by streaming UUIDs directly into a JSON sequence serializer.
• Extend commit lint configuration to allow the "perf" commit type for performance-related changes.

Chores:

• Remove various unused or generated configuration, environment, translation, and build artifact files from the repository.

[CLAassistant]

All committers have signed the CLA.

[sourcery-ai]

Reviewer's Guide

Refactors the Flutter view title bar breadcrumb rendering to use a lazy horizontal ListView with caching for better performance, introduces safer rename popover state handling, optimizes Rust logging and chat UUID serialization to reduce allocations, and updates commitlint to allow perf-type commits along with minor asset/config cleanups.

Flow diagram for Rust logging with thread local buffer

flowchart LR
  on_event[on_event] --> getbuf[LOG_BUFFER.with]
  getbuf --> clearbuf[clear buffer]
  clearbuf --> serializer[serde_json::Serializer::new]
  serializer --> mapser[serialize_map]
  mapser --> writefields[serialize_fields and extra values]
  writefields --> newline[write_all '\n' to buffer]
  newline --> writer[make_writer.make_writer]
  writer --> emit[write_all buffer to output]

Loading

File-Level Changes

Change	Details	Files
Refactor view title bar breadcrumbs to render lazily with ListView.separated and cache breadcrumb widgets based on view-related inputs.	Convert ViewTitleBar from StatelessWidget to StatefulWidget and introduce _ViewTitleBarState to hold breadcrumb cache state. Cache the list of breadcrumb widgets and invalidate the cache when the main view id or name changes. Replace SingleChildScrollView + Row eager layout with a fixed-height horizontal ListView.separated using a lazy itemBuilder and separatorBuilder. Skip the workspace root in the item builder, preserve deleted-view handling, and key tooltip items by view id for stable identity.	frontend/appflowy_flutter/lib/workspace/presentation/widgets/view_title_bar.dart
Make the view rename popover use the latest ViewTitleBloc state while avoiding stale-state issues when opening the popover.	Store the latest ViewTitleState in the ViewTitle widget’s state during Bloc builder execution. Extract the rename popup builder into a dedicated _buildRenamePopover method that uses the cached state when available. Fallback to reading the current bloc state from context if the cached state is not yet initialized, ensuring the text controller is reset consistently.	frontend/appflowy_flutter/lib/workspace/presentation/widgets/view_title_bar.dart
Introduce a reusable thread-local buffer for JSON log formatting to reduce allocations and write log records directly to the writer.	Add a LOG_BUFFER thread_local RefCell<Vec> initialized with a fixed capacity to reuse per-thread buffers. Change span serialization to write into the shared buffer, include a trailing newline, and emit directly through make_writer instead of returning a Vec. Update event formatting to reuse the thread-local buffer, remove the intermediate closure and Vec, append newline, and write directly to the writer.	frontend/rust-lib/lib-log/src/layer.rs
Optimize chat table rag_ids serialization from UUIDs to JSON without an intermediate Vec allocation.	Add a small helper function to serialize a slice of Uuid into a JSON array using serde’s SerializeSeq directly into a Vec. Use the new helper when constructing ChatTable, keeping metadata serialization unchanged and wrapping the result in Some().	frontend/rust-lib/flowy-ai-pub/src/persistence/chat_sql.rs
Allow perf commit type in commit linting rules.	Extend commitlint type-enum configuration to include "perf" alongside existing commit types.	commitlint.config.js
Housekeeping: remove unused or generated files from the repo.	Delete an unused Marathi translation JSON file from appflowy_flutter assets. Delete platform build cache, local Rust cargo config, and sqlite .env files that should not be version-controlled.	frontend/appflowy_flutter/assets/translations/mr-IN.json frontend/appflowy_flutter/macos/build/ios/XCBuildData/PIFCache/project/PROJECT@v11_mod=a7fbf46937053896f73cc7c7ec6baefb_hash=bfdfe7dc352907fc980b868725387e98plugins=1OJSG6M1FOV3XYQCBH7Z29RZ0FPR9XDE1-json frontend/rust-lib/.cargo/config.toml frontend/rust-lib/flowy-sqlite/.env

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[sourcery-ai]

Hey - I've left some high level feedback:

• In ViewTitleBar, _cachedBreadcrumbs is populated but never actually used by the ListView.separated builder (which rebuilds each item from ancestors), so either wire the cache into itemBuilder or drop the cache logic to avoid unnecessary state.
• The previous _buildLockPageStatus widget that appeared after the breadcrumb row is no longer rendered with the new ListView.separated layout; if this status indicator is still desired, it should be reinserted (e.g., as a trailing item) or the unused helper removed.
• The new serialization helpers (serialize_rag_ids_from_uuids, logging JSON writers) rely on multiple unwrap/unwrap_or_default calls, which can panic or silently lose data; consider returning a Result and propagating errors (or at least logging them) to keep behavior predictable and robust.

Prompt for AI Agents

Please address the comments from this code review:

## Overall Comments
- In `ViewTitleBar`, `_cachedBreadcrumbs` is populated but never actually used by the `ListView.separated` builder (which rebuilds each item from `ancestors`), so either wire the cache into `itemBuilder` or drop the cache logic to avoid unnecessary state.
- The previous `_buildLockPageStatus` widget that appeared after the breadcrumb row is no longer rendered with the new `ListView.separated` layout; if this status indicator is still desired, it should be reinserted (e.g., as a trailing item) or the unused helper removed.
- The new serialization helpers (`serialize_rag_ids_from_uuids`, logging JSON writers) rely on multiple `unwrap`/`unwrap_or_default` calls, which can panic or silently lose data; consider returning a `Result` and propagating errors (or at least logging them) to keep behavior predictable and robust.

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