chore: commit pre-existing untracked work + finish archived-doc notes

Commits work that predated this session and was sitting untracked:
qualitative sell strategy module (src/quant_engine), the t20 outcome
ledger cron workflow, the QuantEngine masterpiece roadmap doc, a WBS
execution yaml, and shared Razor Pages partials (page header, delete
confirm modal) with their view models. Verified these build clean
(0 errors, 0 warnings) before committing.

Also includes the "ARCHIVED" header notes on 6 docs archived in the
previous commit - the git-mv landed there, but the note text itself
was missed from that commit's staged file list.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.gitea/workflows/t20_ledger.yml

@@ -0,0 +1,17 @@
+name: Daily T+20 Outcome Ledger Build
+
+on:
+  schedule:
+    - cron: '0 8 * * 1-5'  # KST 17:00 (Mon-Fri)
+  workflow_dispatch:
+
+jobs:
+  build-t20-ledger:
+    runs-on: self-hosted
+    steps:
+      - name: Checkout Code
+        uses: actions/checkout@v3
+
+      - name: Build T+20 Outcome Ledger
+        run: |
+          python3 tools/build_operational_t20_outcome_ledger_v1.py