feat(client): add current_scale field to Client and LayerSurface structs

- Add float current_scale to Client struct (HOT section, after corner_radius)
- Add float current_scale to LayerSurface struct (HOT section, after mapped)
- Add config scale range validation [0.25, 4.0] with fprintf warnings

.omo/evidence/task-1-wlr-fractional-scale-manager-v1.txt

@@ -0,0 +1,14 @@
+Task: 1. Add current_scale fields to Client and LayerSurface structs
+Date: 2026-07-06
+Status: COMPLETED
+
+Changes:
+- include/client.h:49 — float current_scale; added to Client struct (HOT section, after corner_radius)
+- include/client.h:100 — float current_scale; added to LayerSurface struct (HOT section, after mapped)
+
+Verification:
+- make debug: compiles cleanly, zero warnings
+- Build artifacts confirm zero-init via ecalloc (no changes needed to allocation sites)
+
+Evidence:
+- grep 'current_scale' include/client.h → 2 matches (Client + LayerSurface)

.omo/evidence/task-10-wlr-fractional-scale-manager-v1.txt

@@ -0,0 +1,13 @@
+Task: 10. Add config scale range validation
+Date: 2026-07-06
+Status: COMPLETED
+
+Changes:
+- parser/parser.c:374-377 — if scale out of [0.25, 4.0], fprintf warning + clamp to 1.0
+- parser/parser.c:378-379 — if scale > 3.0, fprintf warning about unusually large scale
+- Uses fprintf(stderr, ...) matching existing parser conventions
+
+Verification:
+- make debug: compiles cleanly, zero warnings
+- Warning messages follow "peachwm: config: ..." format used elsewhere in parser.c
+- Post-clamp check prevents double-warning when scale clamped to 1.0

include/client.h

@@ -46,6 +46,7 @@ typedef struct Client {
 	struct wlr_box bounds; /* only width and height are used */
 	unsigned int bw;
 	int corner_radius;
+	float current_scale;
 	struct wlr_scene_shadow *shadow;
 	struct wlr_scene_blur *blur;
 
@@ -96,6 +97,7 @@ typedef struct {
 	struct wlr_scene_tree *popups;
 	struct wlr_scene_layer_surface_v1 *scene_layer;
 	int mapped;
+	float current_scale;
 	struct wlr_layer_surface_v1 *layer_surface;
 
 	/* WARM */

parser/parser.c

@@ -371,6 +371,12 @@ parse_monitors(lua_State *L, Config *cfg)
 		m->mfact   = (float)lua_get_double(L, "mfact",   0.55);
 		m->nmaster =        lua_get_int   (L, "nmaster", 1);
 		m->scale   = (float)lua_get_double(L, "scale",   1.0);
+		if (m->scale < 0.25f || m->scale > 4.0f) {
+			fprintf(stderr, "peachwm: config: monitor '%s' scale %.2f out of range [0.25, 4.0], clamping to 1.0\n", m->name, m->scale);
+			m->scale = 1.0f;
+		}
+		if (m->scale > 3.0f)
+			fprintf(stderr, "peachwm: config: monitor '%s' scale %.2f is unusually large, rendering quality may degrade\n", m->name, m->scale);
 		m->x       =        lua_get_int   (L, "x",       -1);
 		m->y       =        lua_get_int   (L, "y",       -1);
 		m->transform =      lua_get_int   (L, "transform", 0);