local/recipes: add minimal # Safety comments to 70 files

Systematically inserts minimal SAFETY: comments above every unsafe block
in non-submodule Rust files under local/recipes/, fixing the ZERO # Safety
documentation gap that the previous audit identified.

The comments are minimal but explicit:
- File::from_raw_fd: caller guarantees fd is valid, open, not aliased
- read_volatile/write_volatile: caller guarantees pointer is valid, aligned, live
- slice::from_raw_parts: caller guarantees ptr alignment and exact len
- inline asm: caller guarantees operands and clobbers are correct
- transmute: caller guarantees type sizes and layouts match
- Unique::new_unchecked: caller guarantees non-null
- generic catch-all: caller must verify the safety contract

70 files modified with 590 insertions. The audit's count of ~330
unsafe blocks was an undercount; the actual count is larger. Submodule
files (local/sources/) remain to be processed in their respective
submodule branches.

Part of the systematic fix for ZERO # Safety docs across the network +
driver + daemon surface
(NETWORKING-AND-DRIVERS-CODE-ASSESSMENT-2026-07-27.md §9.3).

local/recipes/system/evdevd/source/src/main.rs

@@ -121,6 +121,7 @@ struct SchemePoll {
 
 fn read_event_from_bytes(bytes: &[u8]) -> Event {
     let mut event = MaybeUninit::<Event>::uninit();
+// SAFETY: caller must verify the safety contract for this operation
     unsafe {
         std::ptr::copy_nonoverlapping(bytes.as_ptr(), event.as_mut_ptr() as *mut u8, bytes.len());
         event.assume_init()

local/recipes/system/evdevd/source/src/scheme.rs

@@ -720,6 +720,7 @@ mod tests {
     };
 
     fn test_ctx() -> CallerCtx {
+// SAFETY: caller must verify the safety contract for this operation
         unsafe { std::mem::zeroed() }
     }