aisman

Session 153, Step 8: Fix scroll sync jitter, SVF improvements, implementation origin backend
- AIM-2826 Alt+L / Alt+Ctrl+L step execution history walking
- AIM-2828 Settings for shortcut visual feedback
- AIM-2829 L shortcut resets Alt+L pointer and does not record nav history
- AIM-2832 Add markdown keyboard shortcuts to all text editors
- AIM-2844 Ctrl+Alt+. — code block shortcut
- AIM-2846 Ctrl+Alt+L — link shortcut
- AIM-2848 Fix user story split view scroll sync feedback loop
- AIM-2868 Show implementation origin for IMPLEMENTED issues in session step issues

Outcome:
AIM-2826: Added aim-step-selected selection border to latest step when L shortcut selects session. AIM-2828: Fixed SVF mouseleave close (persistent .on instead of one-time .one). Fixed _callHandler to look up handler function name from fnPath for SVF description, enabling editor shortcuts to show in rectangle. Changed Alt+L/Alt+Ctrl+L SVF style from tip to info (turquoise). AIM-2829: Updated Alt+L SVF text formatting - Session X and Step Y labels now wrapped in bold HTML tags. Text elements at index >= 2 allow inline HTML. AIM-2832/2834/2835/2836/2840/2841/2843/2844/2845/2846/2862/2863/2865/2866/2867: Already fixed by step 7 changes (toggle, shift-to-base mapping, mdFormat guard). AIM-2864: Replaced double-rAF scroll sync with origin-tracking pattern using _syncFromEditor/_syncFromPreview flags with 100ms timeout suppression. AIM-2868: Added IssueImplementedInStepId/IssueImplementedInSessionId columns to Issue model, SQL migration with backfill, updated GetStepIssues API, SetTestResult, and output processing.