feat(cli)!: subcommand CLI, graph tree mode, local include resolution

BREAKING CHANGES:
- `glint <file>` removed; use `glint check <file>`
- `--graph <mode>` removed; use `glint graph [mode]`
- `--graph-out` renamed to `--out` on `glint graph`

feat(cli): ruff-style subcommands — `glint check` and `glint graph [mode]`
feat(graph): `glint graph tree` — terminal job tree with context annotations
feat(graph): context flags (--branch/--tag/--source/--var) on `glint graph`
feat(resolver): recursive local include resolution from disk
fix(resolver): extends unknown base emits warning instead of fatal error
fix(model): script/before_script/after_script accept block scalar string form
test(linter): Samba project CI fixtures as integration tests
chore(build): fix .gitignore to not exclude cmd/glint/ directory
docs: update CHANGELOG, README, ROADMAP for v0.2.0

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

samba-testdata/.gitlab-ci-default-runners.yml

@@ -0,0 +1,30 @@
+# From https://docs.gitlab.com/ee/ci/runners/hosted_runners/linux.html
+#
+#   ...
+#
+#   Runner Tag              vCPUs   Memory   Storage
+#   saas-linux-small-amd64  2       8 GB     25 GB
+#
+# Our current private runner 'docker', 'samba-ci-private', 'shared' and
+# 'ubuntu2204'. It runs with an ubuntu2204 kernel (5.15) and provides an
+# ext4 filesystem, 2 CPU and 4 GB (shared tag) 8G (samba-ci-private tag) RAM.
+#
+
+.shared_runner_build:
+  # We use saas-linux-small-amd64 shared runners by default.
+  # We avoid adding explicit tags for them in order
+  # to work with potential changes in future
+  #
+  # In order to generate valid yaml, we define a dummy variable...
+  variables:
+    SAMBA_SHARED_RUNNER_BUILD_DUMMY_VARIABLE: shared_runner_build
+
+.shared_runner_test:
+  # We use saas-linux-small-amd64 shared runners by default.
+  extends: .shared_runner_build
+
+.private_runner_test:
+  # We use our private runner only for special tests
+  tags:
+    - docker
+    - samba-ci-private