[SaladDay]

One commit per item:

• E5.2: packages.system accepts null and []; a nonempty list is still rejected with the existing typed error.
• E5.5: events per request raised from 64 to the official 16384; stored input budget 512 KiB to 2 MiB and the events route body limit 1 MiB to 4 MiB, so 16384 minimal messages (about 1.75 MiB) fit.
• E5.9: MaxInstructionsBytes on the Harness declaration (MiniMax Code: 32 KiB, native global-instructions limit), checked at Session admission; the daemon's duplicate check is deleted.
• Ledger: E5.3, E5.4, E5.6, E5.7 and E5.8 native differences in the OpenAI compatibility page (en and zh).
• E5.3 code: no change. Blank server_label, empty credential_id and empty allowed_tools names stay rejected because the schema gives no meaning and Core, the daemon and the Vault selection all treat them as invalid.

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