chore(tooling): run ty in CI, coverage gate, drop legacy flake8

.github/workflows/ci.yml

@@ -60,7 +60,7 @@ jobs:
         run: uv sync --extra dev
 
       - name: Run pytest (fast — excludes @pytest.mark.slow)
-        run: uv run pytest tests/ -m "not slow" -n auto --tb=short
+        run: uv run pytest tests/ -m "not slow" -n auto --tb=short --cov=src/spotoptim --cov-branch --cov-report=term
 
   # ── Full suite: nightly schedule + manual dispatch ─────────────────────────
   test-full:
@@ -118,3 +118,7 @@ jobs:
       - name: Ruff
         run: uv run ruff check src/ tests/
         continue-on-error: true
+
+      - name: Type check with ty (non-blocking)
+        run: uv run ty check src/
+        continue-on-error: true

REUSE.toml

@@ -5,7 +5,6 @@ SPDX-PackageDownloadLocation = "https://github.com/sequential-parameter-optimiza
 
 [[annotations]]
 path = [
-    ".flake8",
     ".gitignore",
     ".python-version",
     ".releaserc.json",

pyproject.toml

@@ -32,7 +32,6 @@ dependencies = [
     "spotdesirability>=0.0.1",
     "statsmodels>=0.14.6",
     "dill>=0.4.1",
-    "flake8>=7.3.0",
     "black>=26.1.0",
     "importlib-metadata>=8.7.1",
     "ty>=0.0.29",
@@ -116,3 +115,31 @@ packages = ["src/spotoptim"]
 
 [tool.hatch.build]
 include = ["src/spotoptim/datasets/*.csv"]
+
+# ── Tooling baseline (roadmap #6): converge on the spot* standard ────────────
+# Ruff replaces the removed legacy .flake8. Line length matches black; CI runs
+# `ruff check` non-blocking.
+[tool.ruff]
+line-length = 88
+target-version = "py313"
+
+[tool.black]
+target-version = ["py313"]
+
+[tool.isort]
+profile = "black"
+
+[tool.coverage.run]
+branch = true
+source = ["src/spotoptim"]
+
+[tool.coverage.report]
+# Ratchet: lock in the current ~71% fast-suite coverage so it cannot regress;
+# 68 leaves margin for platform variance. Raise deliberately as coverage
+# improves. The fast CI gate runs pytest with --cov, enforcing this.
+fail_under = 68
+
+# Astral `ty` type checker. Run non-blocking in CI (continue-on-error) so it
+# surfaces type debt without failing the build; tighten to a gate later.
+[tool.ty.environment]
+python-version = "3.13"