Add Big-4 venue mode pills and year 研究趋势 summaries

[znsoftm]

Adds a top-level venue mode for security Big-4 conferences on /papers, plus cached Hub LLM 研究趋势 summaries per conference×year. This follows the screenshot layout: four conference pills sit in the same row as 精选论文 and Hugging Face 每日论文, and an HF-Daily-style year strip replaces the day strip.

Stacked on #31 (security-top tags + venue labels) and the review-stability hub_chat helpers.

UI

• New mode pills: IEEE S&P, ACM CCS, USENIX Security, NDSS
• Selecting a pill leaves the flat catalog / HF Daily view
• Year strip (newest first, 2022–current plus any older years in the catalog) with counts and prev/next
• Paper list is security-top + matching venue + selected year
• 研究趋势 generates when no cache; 查看趋势综述 / 重新生成 when a cache exists (regen requires Hub admin / manage token)
• Reuses the existing HF Daily trend modal (overview / themes / highlights / outlook)
• Other tags keep the current flat list; security-top remains a catalog chip but is not the primary entry

API

• GET /papers/security-trend — index of Big-4 venues and years
• GET /papers/security-trend?venue=usenix-security — year strip for one venue
• GET /papers/security-trend?venue=…&year=2025 (or /papers/security-trend/{slug}/{year}) — public read of a ready trend
• POST same URL — generate; requires Hub admin / SEARCH_TOKEN
• Empty venue×year: clear error, no LLM call
• Failed generate does not overwrite a good cache
• Persist under $PAPERS_DIR/security-trends/{slug}-{year}.json

Venue strings are normalized (IEEE S&P / Oakland, oakland, CCS, Usenix Sec, NDSS, …).

Tests

go test ./internal/api/ ./cmd/proxy/ ./internal/tunnel/ — grouping, cache path, generate auth, empty set (no LLM), persist/skip, failed force keeps cache, UI i18n hooks.

Browser-checked locally: venue pills, year strip, cached trend modal, IEEE S&P switch, return to flat catalog.

How to verify

1. Open /papers (or /papers?venue=usenix-security&year=2025).
2. Confirm the four conference pills sit to the right of 精选论文 / Hugging Face 每日论文.
3. Click USENIX Security (or another venue). The day strip is replaced by a year strip; cards are that venue’s security-top papers for the selected year.
4. Click 研究趋势 (needs translate LLM + manage auth) or 查看趋势综述 if a cache exists. The modal shows headline / 总体图景 / 主题 / 要点 / 展望.
5. Switch back to 精选论文: the list is flat again (no forced year grouping).

Venue pills next to Selected papers and HF Daily
USENIX Security year strip for 2025
Cached USENIX 2025 research-trend modal
IEEE S&P venue mode
venue_mode_pills_year_strip_trend.mp4

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