fix(session): extract meaningful abstract from WM v2 summaries

[liuhang93]

Summary

• _extract_abstract_from_summary returned # Working Memory (the markdown heading) for all WM v2 archives because the v1 regex didn't match and the fallback simply grabbed the first line
• Add a v2-aware regex that extracts the Session Title content line, and improve the final fallback to skip markdown headings

Context

PR #1782 introduced Working Memory v2 with a # Working Memory / ## Session Title structure, but _extract_abstract_from_summary was not updated to handle the new format. As a result, .abstract.md for every WM v2 archive is always the literal string # Working Memory, losing all semantic value.

Before (bug)

# Working Memory       <-- .abstract.md content (useless)

After (fix)

Wang Fang Tencent Senior Backend Engineer Onboarding   <-- actual Session Title

Changes

openviking/session/session.py — 3-tier extraction:

1. v1 format: **One-sentence overview**: <text> (unchanged, backward compatible)
2. NEW v2 format: regex for ## Session Title → skip optional italic description → capture content
3. Improved fallback: iterate lines, skip empty and #-prefixed headings

tests/unit/session/test_wm_v2_guards.py — Added TestExtractAbstract class with 10 test cases covering v1, v2 (with/without italic descriptions), heading-skip fallback, and edge cases.

Test plan

• v1 structured_summary format still works (backward compat)
• v2 with italic section description (_A short and distinctive..._)
• v2 without italic description
• Real WM v2 output from production run
• Never returns # Working Memory as abstract
• Empty input returns empty
• Fallback skips heading lines
• Only-headings input returns empty

Made with Cursor

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PR Reviewer Guide 🔍

Here are some key observations to aid the review process:

🎫 Ticket compliance analysis ✅ 1782 - Fully compliant Compliant requirements: Fix _extract_abstract_from_summary to handle WM v2 format Add v2-aware regex to extract Session Title Improve fallback to skip markdown headings Add comprehensive test cases

⏱️ Estimated effort to review: 2 🔵🔵⚪⚪⚪

🏅 Score: 95

🧪 PR contains tests

🔒 No security concerns identified

✅ No TODO sections

🔀 No multiple PR themes

⚡ No major issues detected

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Category	Suggestion	Impact
Possible issue	Allow underscores in italic description Fix the optional italic description regex to allow underscores within the italic text. The current [^_]+ pattern stops at the first internal underscore, which would fail to match lines like A_title_with_underscores. openviking/session/session.py [1429-1435] title_match = re.search( r"^##\s+Session\s+Title\s*\n" # section header - r"(?:_[^_]+_\s*\n)?" # optional italic description + r"(?:_[^\n]+_\s*\n)?" # optional italic description (allows underscores) r"(.+)", # title content summary, re.MULTILINE, ) Suggestion importance[1-10]: 7 __ Why: The original regex [^_]+ would fail to match italic lines containing internal underscores (e.g., _A_title_with_underscores_). Changing it to [^\n]+ allows underscores while ensuring the pattern doesn't span multiple lines, fixing a potential false negative in v2 format handling.	Medium