0.1.8 Beta1: Replace the internal Kimi K2.6 seed with K2.7 Code #250

Part of #258 (under #248).

Context

CodexHub 0.1.7 already discovers, displays, catalogs, and routes kimi-k2.7-code when Ollama Cloud reports it. This issue does not add K2.7 support and does not own a new Provider/catalog persistence system.

The remaining Beta1 cleanup is only to stop using Kimi K2.6 as an internal bundled/default/test seed and use K2.7 Code consistently. Dynamic provider discovery remains truthful: if an upstream independently reports K2.6, CodexHub may still show it as discovered but must not grant it K2.7 qualification.

Advanced route qualification is owned elsewhere:

• 0.1.8 Beta2: Implement runtime-derived tool compatibility for custom Responses endpoints #58 selects the exact provider/model/protocol capability declaration.
• 0.1.8 Beta3: Complete the generic reversible Code Mode workflow #251 owns the reversible Code Mode codec and its qualification.
• 0.1.8 Beta4: Complete the generic Collaboration V2 workflow #252 owns collaboration V2 exposure and its qualification.

Scope

• Replace internal Ollama Cloud K2.6 bundled/default seeds with kimi-k2.7-code.
• Replace 0.1.8 release fixtures and selectors that still assume the internal K2.6 seed.
• Preserve the existing K2.7 discovery, display-name, context/output-limit, and routing behavior.
• Preserve truthful dynamic discovery of K2.6 without treating it as a qualified Beta1 route.

Acceptance criteria

• Bundled Ollama Cloud defaults use kimi-k2.7-code, not kimi-k2.6.
• 0.1.8 release fixtures/selectors use K2.7 Code.
• Existing K2.7 catalog discovery and routing tests remain green.
• A dynamically discovered K2.6 record remains distinguishable and receives no K2.7 advanced-capability qualification.
• No Provider/catalog transaction framework, recovery journal, global persistence lock, or safe-file redesign is introduced.
• No Code Mode, collaboration V2, or tool_search capability is promoted by this change.

Verification

Verification class: standard. Run the focused provider/catalog tests, affected component suites under repository policy, git diff --check, and the report-only quality gate.

Superseded implementation

PR #261 was closed without merge because it coupled this small seed cleanup to a new cross-language Provider/catalog transaction and recovery system. Its branch is retained only as reference for a future, separately designed persistence effort.