Align three agent skills with README contributor docs.

Adds break/continue to writing-ion-code, ion-build to finding-ion-bugs reproduce steps, and CONTRIBUTING/CHANGELOG to ion-lang orientation.

Author: Cod-e-Codes

.cursor/skills/finding-ion-bugs/SKILL.md

@@ -47,7 +47,7 @@ cargo test test_name -- --nocapture
 **Integration harness (Git Bash on Windows):**
 
 ```bash
-cargo build --release --bin ion-compiler
+cargo build --release --bin ion-compiler --bin ion-build
 cd tests && ./test_runner.sh
 # One test
 cd tests && ./test_runner.sh test_foo.ion

.cursor/skills/ion-lang/SKILL.md

@@ -19,6 +19,8 @@ Ion is a move-only, no-GC systems language transpiled to C. This skill orients y
 |----------|---------|
 | [ION_SPEC.md](../../../ION_SPEC.md) | Authoritative language semantics and grammar |
 | [README.md](../../../README.md) | Build, run, project structure |
+| [CONTRIBUTING.md](../../../CONTRIBUTING.md) | Build, test, lint, and PR expectations |
+| [CHANGELOG.md](../../../CHANGELOG.md) | Release notes by month |
 | [tests/README.md](../../../tests/README.md) | Integration test catalog |
 
 **Compiler pipeline** (see [references/compiler-pipeline.md](references/compiler-pipeline.md)):

.cursor/skills/writing-ion-code/SKILL.md

@@ -83,7 +83,7 @@ Tuple values (flat only, no nesting): `let t: (int, int) = (1, 2);` then `t.0`,
 **Control flow**
 
 - `if` / `else if` / `else` conditions must be `bool`.
-- `while`, `loop`, `for x in expr;` (`for` ends with `;` per grammar).
+- `while`, `loop`, `break`, `continue`, `for x in expr;` (`for` ends with `;` per grammar).
 - `match expr { Pattern => { ... } }` with guards `pattern if cond =>`.
 
 **Methods**