fix: complete memory activation after init self-heal

[LeXwDeX]

Closes #581

Why

When a git project already has AGENTS.md but its initialization stamp is missing, the first /memory on repairs the stamp and then incorrectly returns Memory remains off. The existing regression only exercised the diagnostic method.

What changed

Continue configuration resolution after the activation diagnostic self-heals the initialization stamp. The same request can enable memory and replace an unavailable model. Projects without initialization evidence remain blocked.

Evidence

• Bun 1.3.14: memory, memory_search and production server wiring suites: 116 pass, 0 fail, 400 assertions.
• opencode typecheck passed; lint passed (4846 warnings, 0 errors, unchanged 4850 cap).
• Compiled Bun 1.3.14 debug CLI: --version passed; first /memory on against a fresh isolated database returned Memory on.
• Prepared 1.0.43 release notes and validated both dev.1 and stable rendering.
• New public activation regressions reproduced the original off response before the fix and verify persisted enabled state/model plus status after the fix.
• Independent review: focused regression 5 pass, 0 fail; no blocking findings in the patch or bounded controller/store/identity-lock review.
• Real external model providers are not claimed as validated. Current-head CI is required before merging.

Checklist

• Reproduced and fixed the user-facing activation path
• Added regression coverage for missing, disabled and unavailable-model configuration
• Preserved fail-closed uninitialized-project behavior
• Passed targeted tests and typecheck