feat: Add ref input to publish workflow for tag-specific builds

When using workflow_dispatch, you can now specify a git ref (e.g., v0.1.6)
to build from. This ensures setuptools-scm generates the correct version
instead of a dev version with local identifier that PyPI rejects.

Author: shaia

.github/workflows/build-wheels.yml

@@ -5,7 +5,17 @@ on:
     branches: [main, master]
   pull_request:
   workflow_dispatch:
+    inputs:
+      ref:
+        description: 'Git ref to build from (tag like v0.1.6)'
+        required: false
+        type: string
   workflow_call:
+    inputs:
+      ref:
+        description: 'Git ref to build from'
+        required: false
+        type: string
 
 env:
   # CFD C library version to build against
@@ -29,6 +39,7 @@ jobs:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
+          ref: ${{ inputs.ref || github.ref }}
 
       - name: Checkout CFD C library
         uses: actions/checkout@v4

.github/workflows/publish.yml

@@ -16,6 +16,10 @@ on:
         options:
           - testpypi
           - pypi
+      ref:
+        description: 'Git ref to build from (tag like v0.1.6, or leave empty for default branch)'
+        required: false
+        type: string
 
 # Prevent duplicate runs when release creates a tag
 concurrency:
@@ -25,6 +29,8 @@ concurrency:
 jobs:
   build:
     uses: ./.github/workflows/build-wheels.yml
+    with:
+      ref: ${{ inputs.ref || github.ref }}
 
   build_sdist:
     name: Build source distribution
@@ -34,6 +40,7 @@ jobs:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
+          ref: ${{ inputs.ref || github.ref }}
 
       - name: Set up Python
         uses: actions/setup-python@v5