Bump version to 0.9.7 — bug fixes for float precision, optional modul…

…es, and build system

Mark 0.9.6 as released in CHANGELOG

Bump version to 0.9.5 — extensive bug fixes, memory safety improvemen…

…ts, and documentation

## Compiler

- Lexer: fix off-by-one in PEEK_NEXT/PEEK_NEXT2 boundary checks
- Parser: fix memory leaks in parse_file_expression, parse_variable_declaration,
  and string interpolation handling; fix undersized buffer for escaped strings
- Semacheck2: fix wrong constant in upvalue limit error message (MAX_LOCALS → MAX_UPVALUES)
- Codegen: fix wrong variable name in for-loop register allocation (temp2 → temp3);
  replace multiple early-return paths in visit_postfix_expr with goto cleanup to
  prevent leaking self_list/args arrays; fix register clobbering in
  LOCATION_CLASS_IVAR_OUTER assignment; remove unnecessary NOP for empty statements;
  add VISIT_MOVE_OPT macro to consolidate pragma patterns
- Optimizer: fix constant folding checking wrong register (inst2->p2 → inst2->p1);
  fix NEG optimization writing to wrong destination register (inst->p2 → inst->p1);
  fix OPCODE_SET_FOUR8bit macro missing opcode field
- IR code: convert register allocation from bool[256] array to compact bitmask
  (32 bytes), improving cache efficiency; add bounds checks on empty label stacks;
  add assertion after inst_new allocation

## Runtime / VM

- Fix boolean fast-path comparison incorrectly applied to ordered comparisons
  (LT, GT, LEQ, GEQ) — now restricted to EQ/NEQ only
- Fix crash in gravity_vm_setslot/gravity_vm_getslot when no frames exist
- Fix OPCODE_GET_FOUR8bit macro inconsistency with encoder
- Fix list_iterator_next out-of-bounds read (add bounds check)
- Fix list_storeat duplicate marray_set after resize
- Fix range_contains not handling reversed ranges correctly
- Fix function_exec default-arg filling using wrong index formula
- Fix int_random truncation from gravity_int_t to int
- Fix string_count broken partial-match logic (rewrite using string_strnstr)
- Fix string_upper/string_lower off-by-one (iterated one byte past end)
- Fix string_loadat UTF-8 corruption when reversing multi-byte sequences
- Fix string_loop iterating byte-by-byte instead of by UTF-8 character
- Fix string_iterator/string_iterator_next missing bounds checks
- Fix fiber_abort wrong nargs check (args[0] is self, not the message)
- Fix system_input blindly stripping last char instead of checking for newline
- Fix convert_map2string/convert_list2string losing original pointer on realloc failure
- Fix gravity_class_grow discarding existing ivar values when growing
- Add overflow guard to gravity_function_cpool_add (uint16_t limit)

## Optional Modules

- Math: fix atan2 → atan2f for float builds; use POW macro consistently in
  math_xrt and math_round; fix division-by-zero in math_logx when base=1;
  fix integer overflow in math_random when range endpoint is GRAVITY_INT_MAX;
  fix pointer arithmetic bugs in math_round string truncation
- File: fix memory leak in file_buildpath (result string not freed); fix leak
  in scan_directory recursive path; fix wrong nargs check in file_open; fix
  leaked FILE* when instance creation fails; fix crash on negative read size;
  fix swapped fread/fwrite arguments (size vs count); fix integer overflow
  in read buffer resize; fix typo "enought" → "enough"
- JSON: rewrite string escaping in JSON.stringify to properly escape backslashes,
  quotes, control characters, and handle large strings
- ENV: add Windows compatibility for environ access; simplify key-length loop

## Utilities

- Debug: add buffer overflow protection in DUMP_VM macros; add bounds check in
  opcode_name; fix memory leak in gravity_disassemble
- JSON serializer: fix escape buffer too small (len*2 → len*6+1); add control
  character escaping (\uXXXX); add overflow check
- Utils: fix uninitialized fd in file_read; fix swapped PathCombineA arguments on
  Windows; fix file_name_frompath returning NULL when no separator found; add NULL
  check in string_dup; fix signed arithmetic and missing digit validation in
  number_from_bin

## Shared / Core Data Structures

- gravity_array.h: fix marray_push updating capacity before confirming realloc
  succeeded; add bounds check before write; fix marray_resize/marray_resize0 to
  check realloc result
- gravity_hash.c: fix gravity_hash_memsize counting buckets as nodes; improve
  float hashing precision (%f → %.17g)

## CLI

- Fix memory leaks in unittest_scan (full_path not freed on skip/recurse)
- Fix inline execution buffer leak

## Documentation

- Add comprehensive ARCHITECTURE.md covering the full compilation pipeline, VM
  internals, value system, garbage collector, instruction set, and embedding API
- Add CLAUDE.md with project conventions for Claude Code
- Update README.md: add Building, Usage, and Project Structure sections; update
  line counts to reflect current codebase size; enhance Features list; add links
  to ARCHITECTURE.md

## Tests

- Add 30 new unit tests covering all major bug fixes: bool comparison, string
  operations (count, upper/lower, UTF-8 iteration/reversal), math functions
  (round, logx, xrt, random), file I/O, JSON escaping, range operations,
  list bounds, fiber abort, optimizer constant folding, and more

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

Several leaks and bugs fixed (added new unit test)

Fixed a setter issue that affects some unit tests too

Fixed #379

Fixed an issue due to the introduction of lazy loading a superclass f…

…rom a class.

Added a way to lazy loading extern superclass at runtime

Minor typo fixed

Improved error handling and detection