fix(build): reduce release-build memory pressure on low-RAM devices (#303)

Cargo.toml

@@ -114,10 +114,10 @@ path = "src/main.rs"
 
 [profile.release]
 opt-level = "z"      # Optimize for size
-lto = true          # Link-time optimization
-codegen-units = 1   # Better optimization
-strip = true        # Remove debug symbols
-panic = "abort"     # Reduce binary size
+lto = "thin"         # Lower memory use during release builds
+codegen-units = 8     # Faster, lower-RAM codegen for small devices
+strip = true          # Remove debug symbols
+panic = "abort"      # Reduce binary size
 
 [profile.dist]
 inherits = "release"

README.md

@@ -114,6 +114,7 @@ zeroclaw migrate openclaw
 ```
 
 > **Dev fallback (no global install):** prefix commands with `cargo run --release --` (example: `cargo run --release -- status`).
+> **Low-memory boards (e.g., Raspberry Pi 3, 1GB RAM):** run `CARGO_BUILD_JOBS=1 cargo build --release` if the kernel kills rustc during compilation.
 
 ## Architecture
 
@@ -425,6 +426,7 @@ See [aieos.org](https://aieos.org) for the full schema and live examples.
 ```bash
 cargo build              # Dev build
 cargo build --release    # Release build (~3.4MB)
+CARGO_BUILD_JOBS=1 cargo build --release    # Low-memory fallback (Raspberry Pi 3, 1GB RAM)
 cargo test               # 1,017 tests
 cargo clippy             # Lint (0 warnings)
 cargo fmt                # Format