Clarify upstream import source wording

[shiny-code-bot]

Objective

Update upstream/import wording to reflect that Every Code may pull from both just-every/code and openai/codex, with codex-rs as the local OpenAI mirror.

Current Status

State: Active
Next action: Update local-overlay and workflow docs after the naming ledger lands.
Blocked by: #180 naming ledger.
Last verified: 2026-05-28 after owner clarified future imports may pull more directly from openai/codex.

Finish Line

Docs distinguish just-every/code, openai/codex, codex-rs, and code-rs

Acceptance Criteria

• Use “upstream import sources” for the general category.
• Describe just-every/code as a fork upstream/import source.
• Describe openai/codex / Codex CLI as original/direct upstream and provenance source.
• Keep codex-rs read-only mirror wording clear.
• Keep import workflow docs aligned with current scripts and remote roles.

Relationships

Sub-issue of #179.
Related to #124 upstream intake.
Related to #88 layout confusion.

[shiny-code-bot]

Completed in PR #193.

Renamed the stale docs/local-overlay.md policy doc to docs/upstream-import-policy.md, updated .github/github.json docs routing, AGENTS.md, and fork-health references, and clarified that Every Code owns main; upstream imports are synchronization work into the product branch rather than a long-running local overlay.

Also renamed the local helper and carried-pick manifest away from overlay terminology:

• scripts/local/update-overlay-from-upstream.sh -> scripts/local/update-from-upstream.sh
• scripts/local/overlay-picks.txt -> scripts/local/upstream-picks.txt

The supported public recipe remains just local-upstream-import; the stale local-overlay-update alias was removed.

Validation:

• rg -n "docs/local-overlay\\.md|local-overlay\\.md|upstreamImportPolicy" AGENTS.md README.md docs .github scripts justfile
• rg -n "update-overlay-from-upstream|overlay-picks|local-overlay-update|local-overlay|docs/local-overlay|local overlay|overlay branch|outside the overlay" AGENTS.md docs scripts justfile .github/github.json
• git diff --check
• ./build-fast.sh
• PR Rename upstream import policy docs #193 Blob size policy passed.
• Main Release run 26610990482 passed 8/8.