Fix critical bug where byte offsets and character positions were mixedthroughout the codebase, causing incorrect position reporting for contentwith multi-byte UTF-8 characters (emojis, accented characters, etc.).Changes:- Add position_utils module with byte ↔ character conversion functions- Fix render.rs bug mixing character count with byte offset in end_col- Convert Issue byte columns to DisplayIssue character columns for output- Update actual_offset to convert character positions back to bytes- Improve char boundary checking with proper warnings- Document all position fields as bytes (internal) or characters (display)- Verify Comrak uses byte-based sourcepos (1-based)- Add comprehensive UTF-8 tests with emojis and accented charactersAll 153 existing tests pass. The fix ensures correct position handlingthroughout: tree-sitter/Comrak (bytes) → Issue (bytes) → DisplayIssue(characters) → file operations (bytes).

Fixes panic when byte_offset is in the middle of multi-byte characters(e.g., inside é). Adjusts to nearest boundary before counting chars.Verified with French content. All tests pass.

Fixes panics when running `content fix-flaws` on content with multi-byteUTF-8 characters (e.g., French accented characters like é).The issue occurred when calculating byte offsets for link replacements:- `offset - href.len()` could land inside a multi-byte character- String slicing at invalid boundaries caused panicsChanges:- Add character boundary validation in `collect_suggestions()` to ensure  href start offsets are on valid UTF-8 boundaries- Add defensive checks in `apply_suggestions()` for both start and end  offsets, skipping suggestions with invalid boundaries instead of panicking- Add char boundary check in `calc_offset()` as additional safety net- Add comprehensive tests for multi-byte character handlingThis ensures robust handling of international characters throughout thefix-flaws pipeline (French, German, Japanese, emoji, etc.).

Remove the unnecessary +10 byte margin when calculating search_startposition, which could cause finding wrong instances of duplicate hrefs.The rfind() search is precise enough without the extra margin.Additionally, enhance the warning message when an href cannot be locatedby including the actual content region that was searched. This makesdebugging much easier by showing what text was examined rather than justan offset number.

The fix-flaws command was failing to locate and fix broken links whenhrefs contained HTML entities (&#x27; for ', &lt; for <, etc.). Thisoccurred because:1. Issue hrefs come from HTML output with encoded entities2. Suggestion URLs from redirects also contain encoded entities3. Raw markdown files contain literal characters (', <, etc.)4. The search/replace logic couldn't match encoded strings against literalsThis commit fixes the issue by:- Adding html-escape dependency to rari-tools- Decoding both href and suggestion before searching raw markdown- Decoding href in actual_offset() when calculating positions- Adding tests for HTML entity handlingResult: fix-flaws now successfully updates 22 French docs that werepreviously failing with "Could not locate href" warnings. The fixespreserve literal characters in markdown (no entities added).Fixes issues with French SVG documentation and other files containingaccented characters in URLs.