[k82cn]

Prepares v0.7.0-rc2 on release-0.7.

v0.7.0-rc1 was tagged but its publish run failed in the Release Metadata job, so nothing was published for it (no crates, no wheel, no images). The check compared the flamepy version with uv version --short; the workflow sets CLICOLOR_FORCE: 1, so uv printed the version wrapped in color codes and the comparison failed (0.7.0rc1 != ^[[36m0.7.0rc1^[[39m).

Changes

• Versions 0.7.0-rc1 to 0.7.0-rc2 for the workspace crates, flame-rs and flame-rs-macros; 0.7.0rc2 for flamepy (pyproject.toml, __init__.py, README wheel name); Helm chart appVersion; Cargo.lock. stdng stays at 0.1.9, which has not been published.
• hack/release.sh is not changed here. The fix for the rc1 failure is [release-0.7] fix: read the flamepy version without color in the release metadata check #629 (backport of fix: read the flamepy version without color in the release metadata check #623), which must be merged before tagging because the publish workflow runs hack/release.sh from the tagged commit.
• Release notes: docs/releases/v0.7.0-rc2.md, covering why rc2 exists, the eight changes since rc1 and the two tooling fixes.

This PR is one commit; the net change is the 18 files above.

Checked

• hack/release.sh validate-metadata v0.7.0-rc2 with CLICOLOR_FORCE=1, the way the workflow runs it, passes and reports cargo-version=0.7.0-rc2, python-version=0.7.0rc2, docker-tag=v0.7.0-rc2 and stdng-version=0.1.9. I ran this before the hack/release.sh line was moved out of this PR to [release-0.7] fix: read the flamepy version without color in the release metadata check #629, so it was not repeated on the final tree; without the fix: read the flamepy version without color in the release metadata check #623 change the command fails with the rc1 error.
• flamepy.__version__ is 0.7.0rc2 and matches uv version; cargo fmt --check and git diff --check pass.
• Not run: the registry, Docker and Kubernetes release sanity checks, and cargo package for flame-rs, which needs flame-rs-macros 0.7.0-rc2 published first. The release notes added after the first version of this PR ([release-0.7] fix: allocate and bind only on nodes that are ready #627, [release-0.7] fix: flmadm installs the flamepy wheel it just built #628, [release-0.7] feat: retract executor attributes when cached data is evicted #634) were only read against those pull requests.

Before tagging

Already merged into release-0.7: the backports #618 (#611), #619 (#613), #620 (#614), #621 (#616), #622 (#617), #627 (#625) and #634 (#633), and the tooling fixes #628 (#626) and #629 (#623). Merge #639 (#636, a gang's min_instances and max_instances are tied to its size) first. #640 (#635, the Kubernetes CI setup race) is not in the notes: it changes only CI. Then tag v0.7.0-rc2 on release-0.7. The notes list those backports.