v2.1.2 — Cross-agent install + OpenAlex API key requirement

Patch release — cross-agent install + OpenAlex API key requirement

Three changes since v2.1.1. The OpenAlex item is the one that may require action on existing setups; the rest are additive or behavior fixes. The search pipeline, helper scripts, RCS rubric, and output structure are unchanged — Claude Code users see no difference in behavior.

1. ⚠️ OpenAlex now requires a free API key (action may be needed)

OpenAlex deprecated the mailto= polite pool on 2026-02-13; all API calls now require a free API key. A config that only set openalex_email will stop working against live OpenAlex.

What to do: grab a free key at https://openalex.org/settings/api (instant, no approval) and set openalex_api_key in ~/.paper-search-pro/config.yaml. The free tier is $1/day ≈ 10k list calls / 1k searches — a Standard-tier run uses ~200 calls, so this is plenty. Setup docs, config template, verification scripts, and READMEs all updated to reflect the new requirement; openalex_email is kept as a deprecated/ignored field for backward-compatible configs.

2. Cross-agent install support via $PSP_HOME

The Skill claimed to work on "Claude Code, Codex, any SKILL.md agent," but 22 hardcoded ~/.claude/skills/paper-search-pro paths meant it only really ran under Claude Code. Every invocation now uses $PSP_HOME, resolved once in STEP 0 via a three-layer chain:

1. Explicit injection — the agent substitutes the SKILL.md directory it was given
2. Env var — CLAUDE_SKILL_DIR / CODEBUDDY_SKILL_DIR
3. Filesystem fallback — walks known install locations: ~/.claude/skills, ~/.codex/skills, ~/.agents/skills, ~/.config/opencode/skills, ~/.codeium/windsurf/skills, ~/.config/goose/skills, ~/.cline/skills, ~/.roo/skills, ~/.copilot/skills, plus project-local equivalents

Classifier SubAgent prompts (STEP 6) now pass the expanded absolute rubric path, since each SubAgent runs in its own shell where $PSP_HOME isn't exported. READMEs list the per-agent install paths up front.

3. Japanese / Korean queries route to the English UI (not Chinese)

The old detector sent every CJK character to the Chinese UI — so a Japanese or Korean query produced a Chinese interface, friendly to neither audience. New logic checks hiragana/katakana (U+3041–U+30FF) first → English; then CJK Unified Ideographs → Chinese; Korean Hangul and everything else → English (the international default). Paper titles / abstracts / authors are never translated regardless — only the report UI chrome.

Verification

Both changes were checked by two read-only subagent test passes: the $PSP_HOME resolver behaves correctly across all four scenarios (explicit / env var / fallback / not-found), the language regex routes six representative queries correctly (including the previously-misrouted kanji+hiragana mix 東京大学の最新研究 → EN), all 25 bash blocks pass bash -n, and no hardcoded install paths remain outside legitimate fallback lists and prose examples.

What's NOT changed

• Search pipeline, tier logic, saturation curve, citation chasing — untouched
• Python helper behavior, RCS rubric content, PRISMA-S logger — untouched
• Output file structure (HTML / MD / BibTeX / RIS / CSV / PRISMA-S log) — unchanged
• Claude Code user experience — $PSP_HOME auto-resolves to ~/.claude/skills/paper-search-pro exactly as before