compiler: separate package exports from entry roots

selfhost/cmd/wcc/cgen.ww

@@ -502,10 +502,8 @@ type cgen = struct {
 	// like strlits/ffis. Symmetric with cstage Cg.sep_mode.
 	sepmode: i32,
 	// #99: this unit is a sep DEPENDENCY, not the root/link-entry unit.
-	// Set from `wwiout != nil` in main — the producer passes -I (.wwi
-	// output) to DEP units only; the root's .wwi is stripped (#69), so
-	// wwiout==nil <=> root/link-entry unit. Gates the bare-`main` carve-
-	// out: a dep's `fn main` mangles on its path like any decl; only the
+	// The explicit entry mode is independent of `.wwi` production. It gates
+	// the bare-`main` carve-out: a dep's `fn main` mangles like any decl; only the
 	// root entry stays bare. Like sepmode, NOT reset by cgeninit (per-fn).
 	// Symmetric with cstage Cg.sep_isdep.
 	sepisdep: i32,
@@ -3810,8 +3808,8 @@ fn collectmods(c: *cgen, file: *syntax.node) void = {
 				// #99: under sep a dep unit's main is imported==0 too (its
 				// body is composed with a path-carrying `//ww:module-reset`,
 				// #57), so imported==0 no longer means "root unit" per-unit.
-				// sepisdep (wwiout==nil <=> root/link-entry unit, #69)
-				// re-mangles a dep's main; only the root's stays bare.
+				// Explicit entry mode clears sepisdep independently of export
+				// production; every other package's main remains mangled.
 				if (!syntax.streq(d.str, "main") || d.imported != 0 || c.sepisdep != 0) {
 					let m: *modent = alloc(modent{mname=d.str, nmod=d.nmod, omod=d.nmod, mnext=c.mods})!;
 					c.mods = m;