chore(develop): forward-merge CLAUDE.md and README from main

Brings non-behavioral changes from main into develop:
- CLAUDE.md with code quality conventions (ENG-1762)
- README.md maintenance-mode note

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: prestwich

CLAUDE.md

@@ -0,0 +1,36 @@
+# Signet Node Components
+
+## Branches
+
+The `main` branch is in maintenance and bug-fix mode. The `develop` branch
+contains current work.
+
+## Commands
+
+- `cargo +nightly fmt` - format
+- `cargo clippy -p <crate> --all-features --all-targets` - lint with features
+- `cargo clippy -p <crate> --no-default-features --all-targets` - lint without
+- `cargo t -p <crate>` - test specific crate
+
+Pre-commit: clippy (both feature sets where applicable) + fmt. Never use `cargo check/build`.
+
+## Style
+
+- Functional combinators over imperative control flow
+- `let else` for early returns, avoid nesting
+- No glob imports; group imports from same crate; no blank lines between imports
+- Private by default, `pub(crate)` for internal, `pub` for API only; never `pub(super)`
+- `thiserror` for library errors, `eyre` for apps, never `anyhow`
+- `tracing` for instrumentation: instrument work items not long-lived tasks; `skip(self)` on methods
+- Builders for structs with >4 fields or multiple same-type fields
+- Tests: fail fast with `unwrap()`, never return `Result`; unit tests in `mod tests`
+- Rustdoc on all public items with usage examples; hide scaffolding with `#`
+- `// SAFETY:` comments on all unsafe blocks
+
+## Workspace Crates
+
+All crates use `signet-` prefix. Features exist in:
+- `signet-blobber`: `test-utils`
+- `signet-node-config`: `test_utils`
+
+Other crates (`signet-node`, `signet-node-types`, `signet-rpc`, `signet-db`, `signet-block-processor`, `signet-genesis`, `signet-node-tests`) have no feature flags — lint with `--all-features` only.

README.md

@@ -1,5 +1,8 @@
 # Signet Node Components
 
+> **Note:** The `main` branch is in maintenance and bug-fix mode. The
+> `develop` branch contains current work.
+
 A collection of components for building the Signet node. These components
 implement core node functionality, but are potentially indepedently useful.