Add Kimi AI filter plugin

[id774]

Summary

Adds FilterKimi, a new independent AI filter plugin for Moonshot AI's Kimi API (default model kimi-k3), following the exact architecture of the existing service-specific AI filters (FilterOpenAI, FilterClaude, FilterGemini, FilterSakuraAI). Kimi's Chat Completions protocol happens to be OpenAI-compatible, but this is deliberately its own plugin rather than a mode of FilterOpenAI — matching how FilterSakuraAI (also OpenAI-compatible) is already handled.

Behavior

• New file plugins/filter/kimi.rb, class Automatic::Plugin::FilterKimi.
• Fixed endpoint constant https://api.moonshot.ai/v1/chat/completions (not a Recipe setting), OPEN_TIMEOUT = 10, READ_TIMEOUT = 300 — mirrors sakura_ai.rb/open_ai.rb exactly.
• Required settings: token, model, prompt — validated up front, each missing/empty one raises ArgumentError before any request.
• Request body is exactly {"model", "messages": [{"role": "system", "content": <prompt>}, {"role": "user", "content": <description>}]} — no sampling, reasoning, or tool-use parameters are ever sent.
• Success requires choices[0].finish_reason == "stop" and non-empty choices[0].message.content; reasoning_content, when Kimi sends one, is never read, logged, or written anywhere.
• Non-"stop" finish reason, invalid JSON, or a missing/wrong-shaped response is a permanent Error (not retried) and never overwrites the description.
• Network failures, HTTP 429, and HTTP 5xx are TemporaryError and retried up to the configured retry count with interval seconds between attempts; other failures raise Error immediately. Exhausting retries raises Error and ends the run.
• An item with a blank description is skipped (logged as a warning), leaving it untouched; feed/item count, order, title, link, and date are never touched — only description changes, and only on success.

Compatibility

• No framework, Recipe format, or plugin-loader change.
• No new runtime or development dependency (Gemfile and automatic.gemspec untouched) — only json, net/http, openssl, uri from the standard library, same as the other AI filters.
• No existing AI filter plugin (open_ai.rb, claude.rb, gemini.rb, sakura_ai.rb) was modified.
• VERSION remains 26.09; doc/VERSIONS' existing unreleased v26.09 (Release Date: TBD) entry gets one new bullet (no new version section created).

Security

• The token is read once, sent only as Authorization: Bearer <token>, and never appears in a log line or in any raised exception's message — verified by a dedicated spec.
• TLS certificate verification stays on (OpenSSL::SSL::VERIFY_PEER), matching every other AI filter.
• Only placeholder credentials (YOUR_KIMI_API_KEY) appear anywhere in the diff — no real-looking key.

Documentation

• doc/PLUGINS.md: new FilterKimi — Supported (external) catalogue entry (section 6.3), following the FilterSakuraAI entry's structure; updated the "changing service is changing the one entry" line to include FilterKimi.
• doc/AI_TUTORIAL.md: added a FilterKimi example alongside FilterOpenAI/FilterClaude/FilterGemini in the "change the service by changing one line" section.
• doc/DEPLOYMENT.md: added FilterKimi to the "Supported (external), no gem" table row alongside the other AI filters.
• doc/VERSIONS: one new bullet under the existing unreleased v26.09 entry.

Tests / Validation

• New spec/plugins/filter/kimi_spec.rb (24 examples), modeled on sakura_ai_spec.rb's deterministic Net::HTTP.stub(:start) double — no real network access, no real credential. Covers: missing-setting ArgumentErrors validated before any request; description replacement with title/link/order/count preserved; blank-description skip; exact request shape (endpoint, bearer header, JSON body, system/user roles, absence of any sampling/reasoning/tool parameter); success requiring finish_reason == "stop" plus non-empty content; reasoning_content never leaking into the description; permanent failures (invalid JSON, missing choice/message, non-"stop" finish reason, empty content) leaving the description unchanged; retry on network failure/429/5xx and no retry on other 4xx; exhausted retries raising Error; and the token never appearing in logs or exception messages.

Validation run in this checkout (Ruby 3.3.6):

1. bundle exec rspec spec/plugins/filter/kimi_spec.rb — pass, 24 examples, 0 failures.
2. Full suite (spec/**/*_spec.rb, the pattern rake spec uses) — pass, 447 examples, 0 failures, 0 new skips (only the repository's own pre-existing optional-gem skips: nokogiri, sanitize, fluent-logger, dalli, activerecord). The Kimi spec runs as part of this, not skipped.
3. gem build automatic.gemspec — pass, builds automatic-26.09.gem.
4. bundle exec ruby -Ilib -e "require 'automatic'" — pass, exit 0.
5. bundle exec bin/automatic --version / --help — pass, both exit 0; version prints 26.09.
6. git diff --check — pass, no output.
7. No new runtime or dev dependency — pass, Gemfile/automatic.gemspec untouched.
8. No real API key, voucher code, personal name, or personal email in the diff — pass, only the placeholder YOUR_KIMI_API_KEY and the repository's own existing header contact convention.

Note: this branch (claude/dreamy-sagan-omgzle) is used instead of the originally-specified feature/filter-kimi due to this session's git operating constraints; base master, head claude/dreamy-sagan-omgzle.

🤖 Generated with Claude Code

https://claude.ai/code/session_012batzHd21Na8eJFgc1x2hY

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