fix: render HTML <table> blocks and clean up sidebar snippet (#452)

[rit3sh-x]

Summary

Closes #452.

This PR addresses three related issues that surfaced while implementing the
fix for embedded HTML <table> rendering:

1. Render HTML tables (the original bug). Notes containing raw
   <table> blocks (Obsidian / VSCode style) now render as native
   BlockNote tables when the rich editor opens them. The conversion
   happens in preProcessEditorMarkdown before BlockNote parses, so
   the on-disk content is unchanged in raw mode and only re-serializes
   to GFM if the user actually edits the table in rich mode (matching
   the maintainer's suggestion in the issue thread).
2. Editable header row on /table insert. Previously, /table
   created a table with headerRows: 0, so the visible "header" cells
   were not editable until the user toggled them via raw mode.
   tables.headers is now enabled, and the default slash item is
   overridden to insert with headerRows: 1 directly.
3. Sidebar snippet readability. Tables (HTML or GFM pipe) now show
   up in the note-list snippet as ?? col1 ? col2 ? ? (header preview,
   capped at 80 chars), separated from surrounding prose by a newline.
   The snippet <div> uses white-space: pre-line so the two-line
   clamp shows the table on its own line.

Why this approach

• The HTML->GFM preprocessor stays in the editor swap path - it does not
  touch the on-disk file. Round-tripping (raw -> rich -> raw) is lossy
  by design, matching the maintainer's plan in the issue thread.
• The snippet logic ended up living in three places (Rust runtime, vite
  dev middleware, and an on-save TS path). The PR consolidates the
  walker into a single shared module (src/lib/snippetMarkdownBody.ts)
  so future changes only need to update Rust + that module.

Test plan

• npx tsc --noEmit
• pnpm lint
• pnpm test - 3000+ frontend tests pass; new tests:
  src/utils/htmlTableMarkdown.test.ts (22), the BlockNote round-trip
  in src/components/editorSchema.htmlTable.test.ts (3), the slash
  override in src/components/tolariaEditorFormattingConfig.test.ts
  (2), src/lib/snippetMarkdownBody.test.ts (12), and 3 added cases
  in src/utils/wikilinks.test.ts.
• cargo test --manifest-path src-tauri/Cargo.toml --lib vault::parsing
  • 89 pass, including 4 new HTML / GFM table snippet tests.
• npx playwright test tests/smoke/html-table-rendering.spec.ts
  passes with the issue Bug: HTML tables embedded in Markdown are not rendered #452 minimal repro.
• Native macOS QA per AGENTS.md 1c - I do not have a macOS
  device to run the focus + screenshot scripts. Happy to coordinate
  with a maintainer or with whoever has access.
• CodeScene gate - I do not have access to the project's
  CODESCENE_PAT. The pre-push hook should run on the maintainer side
  before merge.

Notes for the reviewer

• src/utils/wikilinks.ts::extractSnippet is now a thin wrapper around
  the shared walker + the existing stripMarkdownChars. The previous
  duplicated table-unaware logic was the source of the
  "edit-time regression" where the sidebar snippet would revert to raw
  pipes after every save.
• The Windows compile fix in src-tauri/src/commands/system.rs and
  src-tauri/src/git/clone.rs is unrelated to issue Bug: HTML tables embedded in Markdown are not rendered #452 in spirit
  but was required to run cargo test on a Windows dev box. Happy to
  split it into a separate PR if preferred.

[codacy-production]

Not up to standards ⛔

🔴 Issues 59 high · 4 medium

Alerts:
⚠ 63 issues (≤ 0 issues of at least minor severity)

Results:
63 new issues

Category	Results
BestPractice	1 medium
ErrorProne	1 high
Security	58 high
Complexity	3 medium

View in Codacy

🟢 Metrics 193 complexity · 3 duplication

Metric	Results
Complexity	193
Duplication	3

View in Codacy

AI Reviewer: first review requested successfully. AI can make mistakes. Always validate suggestions.

_{TIP This summary will be updated as you push new changes.}

[codacy-production]

Pull Request Overview

The PR introduces HTML table rendering and improved sidebar snippets, but the implementation is currently not up to standards due to high complexity and potential reliability issues. Specifically, src-tauri/src/vault/parsing.rs and src/components/Editor.tsx show massive jumps in complexity without corresponding test coverage. The manual UTF-8 and HTML tag parsing in the Rust backend is brittle and likely to fail on multi-line tags or multi-byte characters. While the TypeScript walker logic was consolidated, the core snippet logic remains duplicated across both languages, increasing the maintenance burden for future updates to the table marker system.

About this PR

• The complex logic for parsing and formatting table snippets ('📊' marker) is duplicated across the Rust backend (src-tauri) and the TypeScript frontend (src/lib). This creates two points of failure for snippet consistency and doubles the effort required for any future formatting changes.

Test suggestions

• Found: HTML to GFM pipe table conversion logic, including escaping of pipe characters and conversion of newlines to
  .
• Found: BlockNote editor parsing of preprocessed tables to verify they are identified as native table blocks with headerRows: 1.
• Found: Slash menu override verifying that clicking the Table item inserts a block with the correct default rows and header settings.
• Found: Snippet extraction logic (both Rust and TS) correctly identifying and formatting the '📊' table marker.
• Found: Playwright smoke test verifying that a note with an embedded HTML table renders as an interactive table in the UI.
• Missing: Unit tests for edge cases like nested tags, multi-line headers, and varying line endings in the Rust snippet extraction logic.
Prompt proposal for missing tests

Consider implementing these tests if applicable:
1. Missing: Unit tests for edge cases like nested tags, multi-line headers, and varying line endings in the Rust snippet extraction logic.

Low confidence findings
• The TypeScript snippet logic uses Regex for HTML processing, whereas the editor uses DOMParser. This discrepancy in parsing strategies may lead to subtle inconsistencies where a note's preview in the sidebar does not match how it is rendered when opened in the editor.

_{TIP Improve review quality by adding custom instructions
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[codacy-production]

_{🔴 HIGH RISK}

The snippet extraction logic in collapse_table_blocks_in_body has significantly increased the cyclomatic complexity of this module. Given the manual string-slicing and regex-based parsing approach, this logic is highly prone to edge-case bugs. Ensure this implementation is backed by unit tests covering nested tags, multi-line headers, and varying line endings.

See Complexity in Codacy

[codacy-production]

_{🟡 MEDIUM RISK}

The logic for tracking nested table states (HTML and GFM pipe syntax) within the snippet walker is becoming quite dense. To improve maintainability, consider refactoring the state management for each table type into separate handler functions or a strategy pattern to isolate buffer management and marker formatting.

See Issue in Codacy

[codacy-production]

_{🟡 MEDIUM RISK}

Suggestion: The manual byte-based UTF-8 iteration and custom utf8_char_len logic are brittle and unidiomatic. Consider using s.chars() or s.char_indices() to safely handle multi-byte characters and prevent potential panics during string slicing.

[rit3sh-x]

@LucaRonin Codacy Static Code Analysis what should I do about this? This was the method I thought to test the functionality.