zc: untyped local const, c precedence for && and ||, import fixes for every module

const name = value; inside a function declares a local constant that takes
the initializer's type. the let quick fix now writes a bare const.

the self-hosted compiler bound || tighter than &&, unlike zc0 and the
readme. no existing source mixed them without parentheses, so only new
code was affected.

missing-name diagnostics and their quick fixes now search every module:
rt, core, run, loaded files, and std, icon and actor scanned from source,
including static groups (std.Text.itoa). typos suggest module exports
(putc -> rt.put_c) and get a change-to fix.

2 files changed, 17 insertions, 0 deletions

diff --git a/tests/langerrors/const_local_no_init.zc b/tests/langerrors/const_local_no_init.zc
new file mode 100644
index 0000000..15832a1
--- /dev/null
+++ b/tests/langerrors/const_local_no_init.zc
@@ -0,0 +1,8 @@
+namespace;
+include rt;
+
+// expect: a const needs an initializer
+fn main() {
+	const k;
+	return 0;
+}
diff --git a/tests/langerrors/const_local_write.zc b/tests/langerrors/const_local_write.zc
new file mode 100644
index 0000000..31220be
--- /dev/null
+++ b/tests/langerrors/const_local_write.zc
@@ -0,0 +1,9 @@
+namespace;
+include rt;
+
+// expect: const storage cannot be modified
+fn main() {
+	const k = 5;
+	k = 6;
+	rt.put_n(k);
+}