Major dependency migration batch (server + src-tauri) #100
Description
This issue tracks consolidated migration work for high-risk Dependabot updates (major/likely-breaking or large grouped updates).\n\nServer-related PRs:\n- #83 hyper 0.14 -> 1.8\n- #85 axum 0.6 -> 0.8\n- #87 jsonwebtoken 9 -> 10\n- #88 tower-http 0.4 -> 0.6\n- #89 thiserror 1 -> 2\n- #92 rand 0.8 -> 0.9\n\nSrc-tauri related PRs:\n- #84 rand 0.8 -> 0.9\n- #90 notify 6 -> 8\n- #91 bincode 1 -> 3\n- #96 rusqlite 0.32 -> 0.38\n\nNPM grouped updates:\n- #98 npm-prod group\n- #99 npm-dev group\n\nPlan:\n1. Consolidate upgrades in dedicated migration branches by area.\n2. Run full CI + manual smoke tests.\n3. Land as reviewed migration PRs instead of many isolated breaking bumps.\n