Merge branch 'feature/builtins-gl' into feature/executor-gl

# Conflicts:
#	src/parser/parser.c

AGENTS.md

@@ -2,6 +2,7 @@
 
 ## Project Structure & Module Organization
 - `src/` holds the shell implementation, with submodules for `builtins/`, `executor/`, `parser/`, and `variables/`.
+- `src/builtins/` currently includes: `cd`, `echo`, `env`, `exit`, `export`, `pwd`, `unset`.
 - `include/` contains public headers used across modules.
 - `lib/` is populated at build time with third-party 42 libraries (libft, get_next_line, ft_printf, ft_args).
 - `docs/` stores project references and manual test notes (see `docs/tests.md`).
@@ -19,6 +20,8 @@
 - The codebase follows 42 **Norminette v4** rules. Run `norminette *.c *.h` (or on specific files) before submitting changes.
 - Keep file names lowercase with underscores (e.g., `src/builtins/echo/echo.c`).
 - Keep headers in `include/` and expose only what modules need.
+- Before adding or changing code, check `allowed.txt` to know which functions are permitted.
+- Any function not listed in `allowed.txt` is not allowed in this project.
 
 ## Parser & Lexer Functionality (Current `src/parser`)
 - Runtime entrypoint is `parse(line, minishell)` from `src/minishell.c` (`readline -> parse -> execute`).
@@ -42,8 +45,18 @@
 
 ## Testing Guidelines
 - There is no automated test runner. Use manual checks in `docs/tests.md` and basic shell behavior checks (pipes, redirects, builtins).
+- A local builtin edge-case script exists at `tests/builtins_edge_cases.sh` (expects a compiled `./minishell`).
 - When debugging memory issues, run under valgrind and use the suppression file in `valgrind/readline.supp`.
 
+## Builtins Status
+- `cd`: handles `HOME` fallback, `cd -` via `OLDPWD`, updates `PWD`/`OLDPWD`, and returns failure on invalid usage (`too many arguments`, missing `HOME`/`OLDPWD`).
+- `echo`: supports repeated `-n` flags (`-n`, `-nnn`) and prints remaining args preserving spaces between tokens.
+- `env`: prints current environment as `KEY=VALUE`; returns failure when called with extra arguments.
+- `exit`: validates numeric argument (with overflow checks), returns `1` on `too many arguments` without exiting, and exits with `2` on non-numeric argument.
+- `export`: supports `NAME=VALUE` and `NAME` (stored as empty value), validates identifiers, and returns failure when any identifier is invalid.
+- `pwd`: prints working directory using dynamic `getcwd` and returns failure if `getcwd` fails.
+- `unset`: validates identifiers and removes matching variables from the environment map.
+
 ## Commit & Pull Request Guidelines
 - Commit messages in this repo use a simple `type: summary` format (examples: `update: ...`, `fix: ...`). Keep summaries short and specific.
 - For PRs, include: