fix: restore Python 3.10/3.11 support and report MCP version

- Drop backslash from f-string expression in markdown/html.py
- That syntax needs 3.12+ (PEP 701) and broke import on 3.10/3.11
- Add Python matrix 3.10/3.12/3.14/3.15 to the Gitea testing workflow
- Pass project_version() to MCPServer; serverInfo.version was empty
- Cover the reported version with an in-memory MCP client test
- Swap deprecated click.get_text_stream for sys.stdin.isatty()
- Add explicit encoding to native host shim and manifest writes
- Add explicit encoding to the registry lock file open
- Add explicit encoding to every read_text/write_text call in tests
- Bump version to 0.16.10 in pyproject.toml and extension/manifest.json
- Move .python-version to 3.15 and refresh uv.lock

Extension code is unchanged; only the manifest version string moved.

Verified with 778 tests on 3.10 through 3.15, plus a strict run using -X warn_default_encoding with EncodingWarning and DeprecationWarning as errors.

.gitea/workflows/testing.yml

@@ -8,6 +8,14 @@ on:
 jobs:
   test:
     runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version:
+          - "3.10"
+          - "3.12"
+          - "3.14"
+          - "3.15"
 
     steps:
       - name: Checkout
@@ -17,10 +25,10 @@ jobs:
         uses: astral-sh/setup-uv@v5
 
       - name: Install dependencies
-        run: uv sync --group dev --managed-python
+        run: uv sync --group dev --managed-python --python ${{ matrix.python-version }}
 
       - name: Run tests
-        run: uv run pytest
+        run: uv run --python ${{ matrix.python-version }} pytest
 
   remote-protocol-compat:
     runs-on: ubuntu-latest