Document generated local manifests and enforce them in CI #296

Description

Section 8 of #288 covers documentation and a tracked-generated-file CI guard. PR #287 contains the proposed implementation but remains unmerged. Dependencies: #295.

Steps to reproduce

Inspection steps (no tests executed):

1. Inspect current scaffold ignore rules.
2. Compare this section’s tasks in local-provision plan with the open branch.
3. Confirm the local-provision contract is still absent from main rather than treating checked-off branch tasks as delivery.

Expected behavior

The section’s contract is present on main and composes with the other local-provision sections without cloud operations during local mode.

Impact

The intended generated-state contract needs consistent docs and a gate that prevents manifests from returning to version control.

Proposed fix

Review and merge this section through PR #287, preserving the tasks below and subsequent umbrella amendments. Reconcile with current main rather than reintroducing removed Fastly runtime-env descriptors.

Dependencies: #295.

Done when

• Task 36: Update 10 docs/ files per the spec's documentation impact table (key wording: "all five adapter manifests, including Axum’s axum.toml, are generated and gitignored" per the July amendment); regenerate docs/.vitepress/dist/
• Task 37: Add CI grep gate enforcing all five manifests + .dev.vars are NOT tracked (regex byte-identical to Task 33's local sanity check)
• The CI gate rejects tracked axum.toml, fastly.toml, spin.toml, wrangler.toml, runtime-config.toml and .dev.vars; Axum is no longer exempt.

Required repository verification: cargo fmt --all -- --check; cargo clippy --workspace --all-targets --all-features -- -D warnings; cargo test --workspace --all-targets; cargo check --workspace --all-targets --features "fastly cloudflare spin"; cargo check -p edgezero-adapter-spin --target wasm32-wasip2 --features spin. These are acceptance requirements, not tests executed during this audit.

Related

#288; local-provision plan; PR #287 is the fully covering open PR. #295

July amendment: all five generated manifests, including axum.toml, are gitignored.