docs: reconcile BOM + Build Guide with v1.2.1 hardware

[daniel-frenkel]

Makes docs/BOM-V2.0.md and docs/wiki-Build-Guide.md agree with each other and with the shipped v1.2.1 hardware. Where the two files disagreed and I wasn't told which was right, I stopped rather than picking — see the open question below.

Applied

1. Zip ties — BOM 1 → 4, breakdown spelled out (1 motor-side elbow + 1 far-side pulley + 2 ring-curtain carriages). The wiki already said 4; now they match.
2. Version header — BOM v1.1 → v1.2.1 (change list expanded to include foam squares + 24 V). Wiki "New in v1.1" banner → "Current hardware — v1.2.1", and its print link hardware/plastics/v1.1 → v1.2.1 (the old path was broken — the folder is v1.1.0, and v1.2.1 is what ships).
3. Foam row — "Foam mounting squares (set of 5) | 5" was ambiguous → "Foam mounting square, 1" | 5" + "five squares per unit", both files.
4. Carriages — added a note to both files: standard build = two carriages (one single-screw, one double-screw). No carriages-per-panel rule exists anywhere in the repo, so I left a TODO rather than invent a ratio.

Regenerated dist/ docx + PDF from the edited BOM source (gitignored, not in this PR).

Report-only (no silent edits)

3. Assembly time — already consistent: every in-repo doc says 20 minutes (wiki-Build-Guide:7, wiki-Home:22, README:45). The only "hours" is 3D-print time (~9 h). Any "1–2 hours" lives in external materials outside this repo. No change needed.
4. Thread-forming screws — the two files agree at 22 (8 body + 14 curtain), but the Build Guide steps do not sum to 22 as written:
   • Body: 8 ✓ — Step 2 (PCB→wall-plate) 4 + Step 3 (wall-plate→housing) 4. (Step 1's "two black M3×10" I read as the 2 flat-head machine screws, not thread-forming.)
   • Curtain rail: only 7 explicitly — Step 1 (long tubes) 2 + Step 2 (pulley end) 1 + Step 3 (carriage sides) 4.
   • Unaccounted toward the BOM's 14: the carriages' "1 + 2 screws on top" (3), any carriage tension screws, and back-tab clamp screws (unspecified, curtain-type-dependent) are not enumerated in the steps.
   • Total explicitly called for ≈ 15, not 22. Flagging per instructions — not editing either file to force a match. The gap is the Build Guide's curtain steps being incomplete, not a BOM/wiki disagreement.

⛔ Open question — item 4 (tool count), NOT changed

The wiki lists three tools (Phillips #1, 2 mm hex, 1.5 mm hex) and says "three common hand tools"; the BOM lists two (Phillips #1, 2 mm hex). Walking the steps, only two are actually called for: Phillips for the plastic thread-forming screws, 2 mm hex for the M3 button-head screws. No step references a 1.5 mm hex or any grub/set screw — the only plausible use is a set screw on the MK8 drive gear (Step 4 just says "fit onto the motor shaft"). Need your call before editing either file — see PR thread.

🤖 Generated with Claude Code

[daniel-frenkel]

Item 4 resolved (owner-confirmed)

The 1.5 mm hex is required — it drives the MK8 drive-gear set screw. So the wiki's "three tools" was right and the BOM + steps were the ones out of date. Applied in 9f1fcdd:

• BOM Assembly Tools: added Hex driver, 1.5 mm ("For the MK8 drive-gear set screw").
• Build Guide Step 4: was "fit the drive pulley onto the shaft" with no set-screw mention → now "fit the MK8 drive gear and secure it with its set screw (1.5 mm hex)", snug-then-fine-tune. Also renamed pulley → gear to match the BOM.

All three (BOM tool list, wiki tool list, and the step) now agree on three tools.

One follow-up: the new 1.5 mm hex BOM row has no store link — I don't have a verified valarsystems.com product URL for it (didn't want to guess one that 404s). Drop the product URL here and I'll add it.

[daniel-frenkel]

Item 6 resolved (owner-confirmed): 22 = 8 body + 14 curtain

The BOM count is correct and both files already agree at 22 — no BOM/wiki change needed.

The only remaining loose end is cosmetic: the Build Guide's curtain-rail steps visibly enumerate just 7 of the 14 (Step 1 long tubes 2 + Step 2 pulley 1 + Step 3 sides 4). The only breakdown consistent with 14 is:

• Long tubes — 2
• Pulley end — 1
• Carriage sides — 4 per carriage × 2 = 8 (i.e. Step 3's "four screws" is per carriage)
• Carriage top screws — 1 + 2 = 3
• = 14 ✓

Optional follow-up: rewrite the curtain steps to enumerate that with a running tally, pending confirmation of (a) Step 3 = per-carriage, and (b) where the 3 top screws are driven. Not changed here.