feat: Discord id cache, resolve fallback, and instant tab-switch

[Keith-CY]

Summary

• Integrate DiscordIdCache into both remote and local slow paths to persist guild/channel id→name mappings across page reloads (discord-id-cache.json)
• Fall back to one-by-one channel resolution when batch openclaw channels resolve fails (e.g. single 404 channel blocking all others)
• Preserve previously-resolved channel names via channel_name_fallback_map when CLI resolution fails, preventing overwrite with raw IDs
• Fix tab-switch showing wrong VPS channels by resolving remote persistenceScope synchronously during render instead of in useEffect
• Change useChannelCache initialization from useEffect to useLayoutEffect for zero-flash tab switching

Test plan

• Unit tests for DiscordIdCache TTL behavior, JSON roundtrip
• Unit tests for parse_resolve_name_map edge cases
• Unit tests for channel name fallback preservation
• Unit tests for loadInitialSharedChannels tab-switch cache behavior
• Manual: switch between VPS instances and verify channels update instantly
• Manual: verify Discord channel names persist across page reloads

🤖 Generated with Claude Code

[dev01lay2]

First review — PR #150

Status

• Merge conflicts — PR is in CONFLICTING state, needs rebase onto main
• CI — Only mirror ran (fork PR limitation). Cannot verify build/test/lint status.

Architecture

Large but well-structured refactor: Discord channel caching with TTL gates, DiscordIdCache for id→name persistence, streaming session analysis via Tauri events, and hook extraction from monolithic components. The layered cache strategy (fast path → TTL gate → full refresh) is sound.

🔴 Blocking

BS 1: Merge conflicts must be resolved before meaningful CI can run.

BS 2: console.log debug statements left in production code
useChannelCache.ts has multiple console.log calls ([useChannelCache] slow path raw channels:, [useChannelCache] fast path raw channels:, etc.) that should be removed or gated behind a dev flag before merge.

BS 3: discovery.rs guild-level placeholder may cause UI confusion
When a guild has no explicit channel list, a placeholder entry is emitted with channel_id == guild_id. Downstream code that filters or routes by channel_id will treat this as a real channel. Consider using a sentinel value or a separate field to mark it as a placeholder.

🟡 Non-blocking suggestions

NBS 1: useChannelCache.ts — ref sync pattern
The channelNodesByInstanceRef is synced via an unguarded useEffect (no deps array). This works but is unconventional — a direct assignment (channelNodesByInstanceRef.current = channelNodesByInstance outside useEffect, like the version in PR #118's fix) is more idiomatic and avoids a render-phase delay.

NBS 2: sessions.rs code duplication
analyze_sessions_sync duplicates the classification/sorting logic that clawpal_core::sessions::classify_session and sort_sessions already provide. Consider reusing the core functions to reduce drift risk.

NBS 3: parse_json_output forward-scanning approach
The new forward-scanning JSON extractor is more robust than the old reverse-scan, good improvement. Minor: the loop will spin on pathological input with many unbalanced brackets — consider adding a max-iterations guard.

NBS 4: DISCORD_CACHE_TTL_SECS = 7 days is aggressive
Channel names rarely change, but guild restructuring (new channels, renamed channels) would be invisible for a week. Consider making this configurable or reducing to 24h.

NBS 5: shell_escape usage in remote session preview
stream_remote_session_preview builds awk commands with shell_escape — ensure this handles session IDs with special characters robustly (e.g. UUIDs are fine, but user-created session names might not be).