docs: sync loop cap config docs

[macro88]

Summary

• anchored the audit to the current origin/main tip c47f413 and confirmed it against the live remote
• updated README.md so the documented config env surface includes GRUGLING_LOOP_CAP
• updated docs/design/code-design.md section 4.6 to include loopCap in the runtime config lifecycle and note that loop cap, like token budgets and temperature, is host-tuned rather than hardcoded
• cross-checked the implementation path in config.example.yaml, src/config/config.ts, src/cli.ts, and src/harness/loop.ts

Verification

• CI=true pnpm install --frozen-lockfile
• CI=true pnpm typecheck
• CI=true pnpm test
• git diff --check

Design doc drift

• affected area: docs/design/code-design.md section 4.6 (Config resolution lifecycle)
• status: resolved in this PR; the doc now matches the shipped loopCap / GRUGLING_LOOP_CAP behavior

[Copilot]

Pull request overview

This PR updates project documentation to reflect the already-shipped loopCap runtime configuration knob and its env var override GRUGLING_LOOP_CAP, aligning docs with the current config resolution lifecycle.

Changes:

• Document GRUGLING_LOOP_CAP in the README’s configuration env var surface.
• Update the design doc’s config resolution lifecycle section to include loopCap as a host-tuned runtime setting alongside token budgets and temperature.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
README.md	Adds GRUGLING_LOOP_CAP to the documented env var overrides and keeps precedence wording consistent with resolveConfig behavior.
docs/design/code-design.md	Extends config lifecycle documentation to include loopCap and clarifies it is host-tuned rather than hardcoded.

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[macro88]

Code-design drift report

I reviewed docs/design/code-design.md against origin/main at c47f413094845f5bd333d5d0be371680c922abe2.

Affected area

• Section 4.6, Config resolution lifecycle

Drift found

• The implementation already exposes loopCap in the profile config and GRUGLING_LOOP_CAP in env overrides, then threads that value from src/config/config.ts through src/cli.ts into the bounded Decide loop in src/harness/loop.ts.
• That design-doc section still listed the host-sized runtime config fields without loopCap, so the documented config lifecycle was incomplete relative to the shipped code.

Evidence checked

• config.example.yaml
• src/config/config.ts
• src/cli.ts
• src/harness/loop.ts

Resolution status

• Resolved in this PR.
• docs/design/code-design.md now documents loopCap as part of the runtime config surface.
• README.md was updated in the same patch so the public env-var list also includes GRUGLING_LOOP_CAP.

No additional unresolved design-doc drift was found during this audit.