docs(m2): #58 EXIF bottom + Photos-ready lineup order

Lock Ty’s decisions: width stations start 6in from EXIF-oriented
photo bottom along the approved length axis; lineup is clean cal,
dimension overlay, then other batch PNGs in capture order.

docs/PHOTOS.md

@@ -16,7 +16,7 @@ Phone capture of one slab → a lined-up set of Woo-compatible inventory PNGs, p
 3. App runs the Milestone 1 workflow on that calibration photo only: Mask → Length axis → Measure (length `L`, thickness, Calculate).
 4. After Calculate, the app applies the approved mask sheet and sensitivity, and the same crop rules (3:4 portrait, 80% fill, transparent PNG, shorter-side floor), to every other photo in the batch.
 5. App adds a second copy of the calibration inventory PNG with dimension overlays burned in (see Dimension overlay).
-6. User sees: all formatted inventory PNGs lined up for preview, and the Milestone 1 calibration details (widths, sqft, bdft, scale, clean calibration PNG) presented as in Measure.
+6. User sees Photos ready: inventory PNGs lined up in this order — clean calibration PNG, then the dimension-overlay copy of the calibration PNG, then the other batch photos in capture order — plus the Milestone 1 calibration details (widths, sqft, bdft, scale) presented as in Measure.
 
 A batch of one photo still works: that photo is the calibration photo; the end set is the clean PNG plus the dimension-overlay copy.
 
@@ -25,7 +25,7 @@ A batch of one photo still works: that photo is the calibration photo; the end s
 1. Batch — add one or more photos; continue when the batch has at least one.
 2. Pick calibration — user chooses which batch photo is the reference.
 3. Mask / Length axis / Measure — Milestone 1 states on the calibration photo only.
-4. Photos ready — lined-up inventory PNGs for every batch photo, plus the dimension-overlay copy of the calibration PNG, plus Milestone 1 numbers.
+4. Photos ready — lineup order: clean calibration PNG → dimension-overlay copy → other batch photos in capture order; plus Milestone 1 numbers.
 
 Device draft restores the last approved state, including the batch and which photo was calibration when those exist.
 
@@ -46,7 +46,14 @@ A second copy of the **calibration** inventory PNG is added to the collection. O
 Orientation follows the **user-approved length axis** from Milestone 1 (not the upright edges of the photo).
 
 - **Length:** dimension graphic beside the wood on the right in axis-space (outside the slab edge along the length direction).
-- **Widths:** stations every 12 in along the approved length axis, starting 6 in from one end of the slab span, continuing while the station is not within 6 in of the other end (stations at 6, 18, 30, … in inches along the axis while ≤ `L − 6`). Each width is drawn across the wood perpendicular to the length axis, with arrow tips on the left and right slab edges and the measurement text on that line.
+- **Widths:** stations every 12 in along the approved length axis, starting 6 in from the **bottom** of the slab span, continuing while the station is not within 6 in of the top (stations at 6, 18, 30, … in inches along the axis while ≤ `L − 6`). Each width is drawn across the wood perpendicular to the length axis, with arrow tips on the left and right slab edges and the measurement text on that line.
+- **Bottom:** after the calibration photo’s EXIF orientation is applied, the bottom edge of that oriented photo establishes which end of the slab is bottom for width stations. Length-axis direction still follows the user-approved Milestone 1 axis; EXIF only picks which end is bottom vs top along that span.
+
+## Photos-ready order
+
+1. Clean calibration inventory PNG
+2. Dimension-overlay copy of the calibration PNG
+3. Remaining batch inventory PNGs in capture order
 
 The clean calibration PNG remains in the set. The annotated copy is extra.
 
@@ -56,7 +63,8 @@ On a phone UAT build:
 
 - User can capture 1–N photos, pick calibration, complete Milestone 1 on that shot, and see every successful batch photo as a 3:4 transparent inventory PNG lined up.
 - Calibration measures match Milestone 1 presentation.
-- Dimension-overlay copy of the calibration PNG is present with black length and width graphics oriented to the approved axis.
+- Dimension-overlay copy of the calibration PNG is present with black length and width graphics oriented to the approved axis; width stations start 6 in from EXIF-established bottom.
+- Lineup order is clean calibration → dimension overlay → other batch photos in capture order.
 - No Woo create. No inference URL.
 
 ## Out of scope