Branding, Excel watermark, live run progress, and uv

- Login and Reports pages: eCare logo, Waystar and Aquilaehr logos (light
  versions for the dark pages), eCare favicon.
- Excel reports: faded eCare/Waystar/Aquila watermark as the sheet
  background on both sheets. Report writer moves to xlsxwriter, the only
  engine that can set a sheet background.
- Reports page: animated run progress (both download lanes piped into the
  Excel sheet) and a plain-language activity feed built from the run log;
  the raw log stays under "Technical log". /status now returns the
  location count.
- Dependencies move from requirements.txt to pyproject.toml + uv.lock;
  Dockerfile installs uv from PyPI and runs uv sync --frozen.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

mek_recon.py

@@ -6,9 +6,9 @@ Aquilaehr: Reports -> Encounter & Claim Monitor -> pick practice -> Export CSV
 -> processing/Aquilaehr/<location>.csv  (same file name as Waystar so the pair lines up)
 Then consolidate.py matches Patient Name + DOS per location -> output/<location>.xlsx
 
-Run:  python mek_recon.py                              both sites at the same time, all locations
-      python mek_recon.py Aquilaehr                    only Aquilaehr
-      python mek_recon.py Waystar "Healing Bridge"     only Waystar, only that location
+Run:  uv run mek_recon.py                              both sites at the same time, all locations
+      uv run mek_recon.py Aquilaehr                    only Aquilaehr
+      uv run mek_recon.py Waystar "Healing Bridge"     only Waystar, only that location
 Login is automatic from .env (WAYSTAR_USERNAME, WAYSTAR_PASSWORD, WAYSTAR_ANSWER_CAR,
 WAYSTAR_ANSWER_JOB, AQUILAEHR_USERNAME, AQUILAEHR_PASSWORD). If something is
 missing/unexpected, finish the login by hand in Chrome; the script waits.