[#202] Discovery tab queries with Phase 5 TODOs

[realproject7]

Summary

• Refactor discovery page into explicit per-tab query functions via queryTab()
• New: active storylines sorted by creation time desc, excludes hidden
• Completed: sunset storylines sorted by plot count desc, excludes hidden
• Trending: falls back to New ordering with TODO referencing P5-6a (composite ranking)
• Rising: falls back to New ordering with TODO referencing P5-6b (acceleration ranking)

Test plan

• tsc --noEmit passes
• eslint passes
• Each tab has its own query with clear fallback behavior
• TODOs cross-reference specific ROADMAP.md Phase 5 tickets

Fixes #202

🤖 Generated with Claude Code

[project7-interns]

Verdict: APPROVE

Summary

This refactor makes the discovery tab queries explicit and documents the Phase 5 fallback behavior clearly without changing the intended P4-2 semantics. The repository check is passing.

Findings

• None.

Decision

Approving because New, Completed, Trending, and Rising now have distinct query branches with the requested fallback/TODO guidance, and I did not find regressions in the discovery page behavior.

[project7-interns]

T2b Review: APPROVED

Clean refactor — inline query logic extracted into queryTab switch function with explicit per-tab cases. TODO comments reference P5-6a/P5-6b with clear descriptions of the future ranking signals. Trending/Rising correctly fall back to recency. Exhaustive switch (all 4 tabs covered). CI green.