feat(core): INCLUDE, error overhaul, sf64 lane, WORDS ALL, .RS

WS-012 -- INCLUDE/INCLUDED:
- Injected source loader (core stays IO-free: CLI installs a
  filesystem reader, web leaves it unset -> defined error). Recursive
  include_file feeds files line-by-line through evaluate, so compile
  state and SEE capture span lines for free. Cycle detection, depth
  cap 16, paths relative to the including file, SOURCE-ID per nesting
  level, parent input restored on success/error/BYE.
- CLI file mode now runs through the include machinery: `wafer x.fth`
  gets file:line error context and a base dir for nested INCLUDEs.
- Unlocks the REMEMBER+INCLUDE reload loop.

WS-008 -- error reporting remainder:
- Errors inside included files carry `file.fth:12:` context
  (anyhow context chain; CLI prints {e:#}).
- describe_uncaught now returns typed WaferError::UncaughtThrow
  { code, message } -- display text unchanged, THROW code reachable
  via downcast for CLI/web consumers.
- compile_word emits a WASM name section; wasmtime trap backtraces
  name the faulting word and runtime_native prefixes "in <WORD>:".
  Batch/consolidated modules stay unnamed (no name plumbing there;
  boot primitives rarely trap).

WS-003 -- SwiftForth correctness lane:
- compare_all_programs_sf64 runs the program corpus with sf64 as
  oracle; whitespace-token comparison (sf64 prints numbers
  space-prefixed and echoes piped lines). 34/35 parity; dot-quote
  skipped (interpret-mode ." is a SwiftForth no-op). #[ignore]d like
  the gforth lane; `just compare-correctness` runs both.

WS-011 leftovers:
- WORDS ALL: grouped full view -- one section per wordlist (search
  order first), then internal words, each with counts. Backed by
  Dictionary::visible_entries (name, wid, internal); visible_words
  now derives from it.
- .RS / RDEPTH: return-stack introspection in boot.fth over a new
  RP@ primitive (IrOp::RpFetch); BEGIN/WHILE walk so the walk never
  touches the stack it prints. SPACES clamped per 6.1.2230.

549 unit + 11 compliance + 9(+2) comparison + 5 crypto + 1 bench
green; fmt/clippy clean; --no-default-features and wasm32 web checks
pass.

crates/core/src/see.rs

@@ -194,6 +194,7 @@ fn write_op(out: &mut String, op: &IrOp, depth: usize, resolve: &dyn Fn(WordId)
         // -- System --
         IrOp::Execute => "execute".into(),
         IrOp::SpFetch => "sp@".into(),
+        IrOp::RpFetch => "rp@".into(),
 
         // -- Float stack --
         IrOp::FDup => "fdup".into(),
@@ -342,6 +343,7 @@ mod tests {
             IrOp::Type,
             IrOp::Execute,
             IrOp::SpFetch,
+            IrOp::RpFetch,
             IrOp::FDup,
             IrOp::FDrop,
             IrOp::FSwap,