feat(sdk): improve read_url error diagnostics and html table extraction

[nilaymallikk]

Summary

Closes #1121.

Enhances the read_url tool in @codebuff/sdk and common tool schemas:

• Structured Error Diagnostics: Adds typed error classifications (errorCode such as HTTP_ERROR, BLOCKED_ADDRESS, INVALID_URL, TOO_MANY_REDIRECTS, UNSUPPORTED_CONTENT_TYPE, RESPONSE_TOO_LARGE, TIMEOUT, ABORTED) and forwards HTTP status codes (e.g. 404, 429, 500) so caller agents can differentiate retryable rate-limits from permanent errors.
• HTML Table Extraction: Added formatHtmlTables pre-processor during HTML readable text extraction to transform <table> elements into structured GitHub-Flavored Markdown tables instead of flattening cells into unformatted lines.

Scope

All changes are strictly scoped within:

• sdk/src/tools/read-url.ts
• sdk/src/__tests__/read-url.test.ts
• common/src/tools/params/tool/read-url.ts

Verification

• Passed unit tests: bun test sdk/src/__tests__/read-url.test.ts (21 pass)
• Passed full SDK test suite: bun test sdk/src/__tests__/ (470 pass)
• Passed CI build and packaging: bun run ci
• Passed binary smoke test: bun cli/scripts/smoke-binary.ts cli/bin/freebuff

Good instinct and correctly scoped to sdk/common (not touching any forbidden paths). The errorCode/status additions to read_url are backward-compatible (optional fields) and well-tested for the HTTP_ERROR/UNSUPPORTED_CONTENT_TYPE/INVALID_URL/BLOCKED_ADDRESS/TOO_MANY_REDIRECTS paths.

Two things need fixing before this is portable:

1. Table cell escaping is missing. In formatHtmlTables (read-url.ts ~L200-235), cell text is joined with | but never escapes literal | characters that may appear in the extracted text (e.g. a table cell containing a|b). That will silently corrupt the resulting markdown table structure. Needs cell.replace(/\|/g, '\|') or similar before joining.

2. Error classification via string matching is fragile. isInvalid (L449-452) and isTooLarge (L534-537) key off substrings of thrown error messages ('Only http:// and https:// URLs are supported', 'Response is too large', 'Response exceeded') rather than typed errors from assertUrlAllowed/fetch. If those message strings ever change, the errorCode silently degrades to the wrong classification with no test to catch it. Prefer having assertUrlAllowed throw a typed error (e.g. {code, message}) rather than matching text.

3. Test coverage gap: you added TIMEOUT, ABORTED, and RESPONSE_TOO_LARGE to the error-code union and wrote classification logic for them, but there's no test exercising any of those three paths — exactly the paths most likely to regress given point 2.

Also worth a nested-table caveat: the regex-based <table>...</table> matcher will misbehave on nested tables (rare in practice, but worth a comment/guard).

Address the pipe-escaping bug and add tests for the untested error codes and this becomes straightforward to port.

Apologies — this PR was auto-closed by GitHub when we force-pushed a history rewrite of this repository (repository maintenance; every commit SHA changed). That was not a judgment on this PR, and GitHub does not allow us to reopen it because the commits it was based on no longer exist in the new history.

If you'd like to continue with this change: rebase your branch onto the new main (or recreate it from a fresh clone) and open a new PR — feel free to link back to this one for context, and we'll pick up the review there.

Sorry for the churn, and thanks for contributing.