Verify content rewriting pipeline is platform-agnostic (PR 8)

[prk-Jr]

Summary

• Verifies that the content rewriting pipeline (html_processor, streaming_processor, streaming_replacer, rsc_flight) has zero Fastly imports and requires no PlatformContentRewriter trait — future adapters (PR 16/17) need not implement any content-rewriting interface.
• Documents this outcome in platform/mod.rs, html_processor.rs, and streaming_processor.rs so it is discoverable for Cloudflare, Axum, and Spin adapter authors.
• The publisher.rs handler layer uses fastly::Body/Request/Response at its function boundaries, but this is an HTTP-type coupling addressed in Phase 2 (PR 11), not a content-rewriting concern.

Changes

File	Change
crates/trusted-server-core/src/platform/mod.rs	Add "Platform-Agnostic Components" section documenting no PlatformContentRewriter trait is needed
crates/trusted-server-core/src/html_processor.rs	Add # Platform notes section confirming zero Fastly imports
crates/trusted-server-core/src/streaming_processor.rs	Add # Platform notes section confirming StreamingPipeline::process is generic over R: Read + W: Write
crates/trusted-server-adapter-fastly/src/platform.rs	Fix unresolved intra-doc link (EdgeRequest → edgezero_core::http::Request) caught by cargo doc
docs/superpowers/plans/2026-03-31-pr8-content-rewriting-verification.md	Add implementation plan for this PR

Closes

Closes #489

Test plan

• cargo test --workspace
• cargo clippy --workspace --all-targets --all-features -- -D warnings
• cargo fmt --all -- --check
• JS tests: cd crates/js/lib && npx vitest run
• JS format: cd crates/js/lib && npm run format
• Docs format: cd docs && npm run format
• WASM build: cargo build --package trusted-server-adapter-fastly --release --target wasm32-wasip1
• Manual testing via fastly compute serve

Checklist

• Changes follow CLAUDE.md conventions
• No unwrap() in production code — use expect("should ...")
• Uses tracing macros (not println!)
• New code has tests
• No secrets or credentials committed

[aram356]

Summary

Documentation-only PR (plus one intra-doc link fix) that verifies the content rewriting pipeline is platform-agnostic. Core claims are accurate — html_processor, streaming_processor, streaming_replacer, and rsc_flight have zero fastly imports. Good separation of concerns that saves future adapter authors from implementing unnecessary abstractions.

Non-blocking

🤔 thinking

• Broken intra-doc link syntax in html_processor.rs:12 — `impl `[`StreamProcessor`] has an awkward space between backtick-wrapped impl and the link. Consider `impl` [`StreamProcessor`] or plain `impl StreamProcessor`.
• Missing blank line before use in html_processor.rs:17-18 — The original file had a blank line between the doc block and imports. Lost in the edit; inconsistent with streaming_processor.rs which has the blank line.

♻️ refactor

• publisher.rs caveat in platform/mod.rs:31-37 — The handler-coupling detail feels like it belongs in publisher.rs itself rather than the platform module doc. Consider moving it there and keeping platform/mod.rs focused on what adapters need to know.

🌱 seedling

• PR number references in doc comments may age poorly — "PR 8", "PR 11", "PR 16/17" will be opaque without EdgeZero migration context. Consider more descriptive labels (e.g., "the HTTP-type migration" instead of "PR 11").

⛏ nitpick

• StreamingPipeline::process<R: Read, W: Write> in platform/mod.rs:27 — Angle brackets are plain text, not a link or code. Should be wrapped in backticks or use an intra-doc link.

👍 praise

• Good call not introducing a PlatformContentRewriter trait — the pipeline is already generic.
• Nice catch fixing the unresolved EdgeRequest doc link.

CI Status

• integration tests: PASS
• browser integration tests: PASS
• prepare integration artifacts: PASS

[aram356]

Summary

Documentation-only PR that verifies the content rewriting pipeline is platform-agnostic and documents this for future adapter authors. The doc comments are well-structured and the separation of concerns (platform-agnostic pipeline vs platform-coupled handler layer) is correctly captured.

Blocking

🔧 wrench

• Unresolved intra-doc link: StreamingPipeline::process in platform/mod.rs:26 does not resolve — StreamingPipeline is not in scope from the platform module. This is a new cargo doc warning not present on the base branch. Needs the full path.

• Inconsistent PR number references: streaming_processor.rs still uses opaque "PR 8" (line 11) and "PR 16/17" (line 17) while html_processor.rs and platform/mod.rs were updated to descriptive labels in commit 2333227. This file was missed.

Non-blocking

🤔 thinking

• 350-line plan document: docs/superpowers/plans/2026-03-31-pr8-content-rewriting-verification.md is an agentic implementation plan with task checkboxes and bash commands — 350 lines of process artifact for ~55 lines of doc comment changes. It also still contains opaque "PR 8"/"PR 11"/"PR 16/17" references. Is this pattern intended to be kept long-term, or should plans be cleaned up after the PR ships?

CI Status

• integration tests: PASS
• browser integration tests: PASS
• prepare integration artifacts: PASS