fix: close type-safety holes found by adversarial review; update docs

Review findings (all reproduced, then fixed and re-verified):
- '^x' leaked as a raw address into any builtin context (s <- ^x printed
  the variable's bytes as a C string; NOT ^x, '&', and ^x = ^x compiled).
  Address-of is now rejected everywhere except a pointer-typed target.
- A whole-array variable passed the nominal gate as a value of its
  ELEMENT type (s <- arrayOfSeason stored the raw data pointer; = on it
  emitted invalid IR). Whole arrays are now rejected as operands and as
  coercion sources; array parameters are unaffected.
- Enum values smuggled into INTEGER through array subscripts and DECLARE
  bounds (a[Autumn], ARRAY[Spring:Winter]); both now go through
  emitCoercedExpr like every other INTEGER context.
- An array DECLAREd inside an IF/WHILE/REPEAT/FOR body and used after the
  block was a wild-pointer write (constant bounds) or a verifier dump
  (runtime bounds). Arrays are now block-scoped: control-flow bodies
  snapshot and restore the ArrayTable, so escape is a clean compile error.
- Duplicate parameter names silently shadowed (BYREF write-back defeated);
  now a parse error. Trailing comma in parameter lists accepted; now a
  parse error consistent with every other list.
- A variable/array/parameter/function could reuse a TYPE name; reserved.
- RETURN with a value inside a PROCEDURE was silently discarded (control
  did not return); now an error, as is a bare RETURN in a FUNCTION.
- INPUT r.f mis-parsed into a three-error cascade; now one clear error.
- Assigning to an enum constant now says so instead of 'Unknown variable'.

Docs: ARCH/CONVENTIONS/EXTENDING/SUBSYSTEMS/PITFALLS rewritten for the
TYPE system (ABI additions, nominal-typing invariants, admission-gate
doors, array-parameter ABI, new recipes, new sharp edges); README
features/TODO updated — random files are unblocked.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/README.md b/README.md
index 79250d2..dd08059 100644
--- a/README.md
+++ b/README.md
@@ -18,13 +18,21 @@ IDK WHAT HAPPENDED IT IS 100% AI-GENERATED DO NOT OPEN ANY ISSUES JUST CLONE AND
 - text file handling (OPENFILE/READFILE/WRITEFILE/CLOSEFILE/EOF) with runtime misuse
   checking (wrong mode, not open, read past EOF, ... all die with a clean `[Fatal]`
   message instead of corrupting anything)
+- user-defined types (CIE §4): enumerated types (with runtime range checking on
+  `enum ± INTEGER`), pointers (`^x` / `p^`, strict nominal typing, null-deref dies
+  with `[Fatal]` instead of segfaulting — linked lists work, `TYPE NodePtr = ^Node`
+  may forward-reference), records (nested, arrays of records, `Form[i].Field <- x`)
+- whole arrays and records as FUNCTION/PROCEDURE parameters (`ARRAY OF T` or
+  `ARRAY[l:u,...] OF T` as a checked contract; BYVAL really copies), with the
+  spec-correct sticky BYREF/BYVAL and BYREF-is-procedure-only rules from §8.3
 - ultra-fast compiling & executing
 
 ## TODO
 
 - search for `TODO` in my code
-- type
-- random files (OPENFILE FOR RANDOM / SEEK / GETRECORD / PUTRECORD) — needs `type` first
+- random files (OPENFILE FOR RANDOM / SEEK / GETRECORD / PUTRECORD) — `type` is done, unblocked
+- SET types (`SET` / `DEFINE` are reserved and give a clear "not implemented" error)
+- CASE OF, CONSTANT, DATE
 
 
 ## Dependencies