Modularize Go files, extract JS to static, implement competitor pricelists

Go refactoring:
- Split handlers/pricing.go (2446→291 lines) into 5 focused files
- Split services/stock_import.go (1334→~400 lines) into stock_mappings.go + stock_parse.go
- Split services/sync/service.go (1290→~250 lines) into 3 files

JS extraction:
- Move all inline <script> blocks to web/static/js/ (6 files)
- Templates reduced: admin_pricing 2873→521, lot 1531→304, vendor_mappings 1063→169, etc.

Competitor pricelists (migrations 033-039):
- qt_competitors + partnumber_log_competitors tables
- Excel import with column mapping, dedup, bulk insert
- p/n→lot resolution via weighted_median, discount applied
- Unmapped p/ns written to qt_vendor_partnumber_seen
- Quote counts (unique/total) shown on /admin/competitors
- price_method="weighted_median", price_period_days=0 stored explicitly

Fix price_method/price_period_days for warehouse items:
- warehouse: weighted_avg, period=0
- competitor: weighted_median, period=0
- Removes misleading DB defaults (was: median/90)

Update bible: architecture.md, pricelist.md, history.md

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/templates/base.html

@@ -21,6 +21,7 @@
                     <div class="hidden md:flex space-x-2">
                         <a href="/lot" class="{{if eq .ActivePage `lot`}}bg-orange-50 text-orange-700{{else}}text-gray-600 hover:text-gray-900 hover:bg-gray-50{{end}} px-3 py-2 text-sm rounded-md transition">LOT</a>
                         <a href="/vendor-mappings" class="{{if eq .ActivePage `vendor_mappings`}}bg-orange-50 text-orange-700{{else}}text-gray-600 hover:text-gray-900 hover:bg-gray-50{{end}} px-3 py-2 text-sm rounded-md transition">Vendor mappings</a>
+                        <a href="/admin/competitors" class="{{if eq .ActivePage `competitors`}}bg-orange-50 text-orange-700{{else}}text-gray-600 hover:text-gray-900 hover:bg-gray-50{{end}} px-3 py-2 text-sm rounded-md transition">Конкуренты</a>
                         <a href="/admin/pricing" class="{{if eq .ActivePage `admin`}}bg-orange-50 text-orange-700{{else}}text-gray-600 hover:text-gray-900 hover:bg-gray-50{{end}} px-3 py-2 text-sm rounded-md transition">Администратор цен</a>
                         <a href="/setup" class="{{if eq .ActivePage `setup`}}bg-orange-50 text-orange-700{{else}}text-gray-600 hover:text-gray-900 hover:bg-gray-50{{end}} px-3 py-2 text-sm rounded-md transition">Настройки</a>
                     </div>