fix: stabilize learning path, reliability and legacy Windows builds

Unify beginner syntax while preserving compatibility, repair ownership and parser guards, add verified distribution tooling and VC6 Windows 98 build inputs, and clarify documentation and release status. Preserve DOS build-input line endings and exclude generated binaries/caches.

docs/RUNTIME_LIMITS.md

@@ -1,33 +1,32 @@
-# Runtime Guards & Limits (Beta25)
+# Current runtime guards
 
-Claro includes optional safety limits to prevent hangs and memory abuse.
+These are implemented guardrails, not a sandbox or a promise that arbitrary
+scripts have bounded resource use.
 
-## 1) Step limit (runaway protection)
-Environment variable:
-- `CLARO_STEP_LIMIT=200000`
+- **Function/method calls:** at most 256 active calls. Excessive recursion raises
+  a Claro error. Other limits can stop a program earlier.
+- **Expressions:** at most 128 nested parser levels, covering parentheses and
+  unary operations. Excessive nesting produces a diagnostic instead of
+  continuing recursive parsing.
+- **Control blocks:** at most 128 additional nested control-block frames. The
+  runtime and syntax checker reject deeper blocks. Function-call frames have
+  their own guard.
+- **HTTP response bodies:** limited to 1,048,576 bytes by the existing HTTP path.
 
-Stops a program if it executes too many steps/lines.
+Malformed expressions such as a lone `!`, an unclosed quote/parenthesis,
+a missing operand, or trailing expression tokens are rejected by the runtime.
+Use `NOT` for logical negation; `!=` remains a supported comparison.
 
-## 2) File size limit
-Environment variable:
-- `CLARO_MAX_FILE_BYTES=16777216` (default 16 MiB)
+## Not provided
 
-Applies to:
-- `READ FILE ...`
-- `WRITE FILE ... WITH ...`
-- `APPEND FILE ... WITH ...`
+The former beta document described `CLARO_STEP_LIMIT`, `CLARO_MAX_FILE_BYTES`,
+and `CLARO_MAX_JSON_BYTES`. Those environment controls are not implemented in
+the current `src/claro.c`; do not depend on them. The original document is
+preserved under [history](history/RUNTIME_LIMITS_BETA25.md).
 
-## 3) JSON size limit
-Environment variable:
-- `CLARO_MAX_JSON_BYTES=8388608` (default 8 MiB)
+Ordinary intentional loops can still run indefinitely. This checkpoint does
+not establish a general JSON recursion limit, global file/output-size limit,
+CPU budget, or untrusted-script protection. Scripts and `RUN COMMAND` execute
+with the user's permissions.
 
-Applies to:
-- `PARSE JSON ...`
-- `MAKE JSON ...`
-- `MAKE JSON PRETTY ...`
-
-## 4) Error output
-Runtime errors include:
-- `file:line: message`
-- stack trace (CALL chain)
-- and JSON parse errors include `Near: ...` snippet
+See [reliability verification](RELIABILITY.md) for the tested scope.