uv dev environment, README writing pass, publish hygiene

- pyproject.toml + uv.lock: uv-managed dev environment (uv sync /
  uv run pytest). requirements.txt stays: KiCad builds the plugin's
  runtime venv from it and the PCM zip packages it.
- README: em-dash and run-on cleanup (34 -> 22, the rest deliberate),
  split the 120-word THT solder-joint sentence, fix the documented
  ADAPTIVE_MAX_CELL_UM value (2 mm -> 1 mm, config has 1000 um), fix
  the *Packaging / publishing* cross-reference, dev sections now use
  uv sync / uv run.
- LLM disclaimer: "most commits" carry the trailer (32 of 39), figures
  claim now excepts the hand-drawn hole cross-section, reference the
  UT3513+ measured-vs-computed validation.
- .gitignore: local AI-tooling artifacts; deploy scripts exclude
  pyproject.toml/uv.lock; error-figure title punctuation aligned with
  the other window titles.

deploy.ps1

@@ -30,7 +30,8 @@ if ($Mode -eq 'Junction') {
     New-Item -ItemType Junction -Path $dst -Target $src | Out-Null
     Write-Host "junction created: $dst -> $src"
 } else {
-    $exclude = @('.venv', '.git', 'tests', 'tools', '__pycache__', '.pytest_cache')
+    $exclude = @('.venv', '.git', 'tests', 'tools', '__pycache__', '.pytest_cache',
+                 'pyproject.toml', 'uv.lock')
     New-Item -ItemType Directory -Force $dst | Out-Null
     Get-ChildItem $src -Force | Where-Object { $exclude -notcontains $_.Name } |
         ForEach-Object { Copy-Item $_.FullName -Destination $dst -Recurse -Force }