docs: Apple Core AI cookbook and Agent Skill for MiniCPM5-2B and MiniCPM5-1B (iPhone / iPad / Mac)

[john-rocky]

Thanks for the per-backend cookbooks and Agent Skills. This adds Apple Core AI as a deployment route, in the shape the table uses: a cookbook and a paired skill, so "run it in an iPhone / iPad / Mac app" has a row in minicpm5-deploy.

What it adds:

• docs/deployment/coreai.md and skills/minicpm5-deploy-coreai/SKILL.md: the Swift path through the community CoreAIKit package, Apple's own CoreAILanguageModels path, the conversion recipe, on-device numbers, and pitfalls. Both sizes.
• minicpm5-deploy: one checkpoint row, one decision-matrix row, one default pick, one line on the sanity check.
• README.md / README-cn.md: one row in each deployment table (2B and 1B), and coreai in the router's route list.

The bundles are community int8 conversions (per-block-32 scales; 2B 2.7 GB, 1B 1.1 GB). Measured: 2B 22.4 tok/s decode on iPhone 17 Pro and 127.6 on M4 Max; 1B 61.7 and 246.6. Both answer 1+1=? and stop, on CoreAIKit and on Apple's llm-runner.

The 1B is the second commit. Its earlier bundle did not stop at the end of a turn; the cause was on my side (a per-channel int8 export whose LM head lost every vocab id above ~65024, <|im_end|> included). The bundle was rebuilt with per-block-32 scales, the stop is now part of the zoo's gate, and the cookbook names the revision to use.

If any wording or placement should be different for this repo, tell me and I will change it.

[john-rocky]

Added MiniCPM5-1B in a second commit (cookbook, skill, router, README rows), as the description promised. The earlier 1B bundle's stop problem was on my side and is fixed; the description has the details. Title and description updated to cover both sizes.