fix(control-plane): pin UTF-8 on the packaged stride schema read

[JasonBuildAI]

Goal And Delivered Outcome

• Outcome basis / optional anchor: reproduced defect (self-contained repair; no board row or RFC needed).
• Goal/source and gap: PR feat(replan): add versioned structured stride policy and decision feedback #6298 (7a315eff2) added loopx/control_plane/work_items/stride_policy_codec.py, which reads the packaged loopx/control_plane/stride_strategy_schema.json with Path.read_text() and no codec. That broke the shipped-runtime UTF-8 guard tests/test_loopx_text_io_utf8.py (the [Bug]: Windows non-UTF-8 locale — Path text I/O decodes structured state files with the locale encoding #4941 class guard introduced with fix(usage-ping): pin UTF-8 on the state reads and guard the class #5160/fix(cli): pin the shipped CLI's own stdio to UTF-8 #6119), which fails on current main for every contributor. The read sits on the CLI configuration path (capabilities/configuration_ui.py, cli_commands/registry_admin_configure.py, execution_profile.py, capabilities/todo_replan_cadence/machine_defaults.py), so on a non-UTF-8 host the schema would be decoded with the host locale codec.
• Observable before → after, with the validation row that proves it: uv run --extra test python -m pytest -q tests/test_loopx_text_io_utf8.py on main at 64bfb8343 reports 1 failed, 1 passed naming loopx/control_plane/work_items/stride_policy_codec.py:16; on this head it reports 2 passed. Validation row: unit.
• Issue/task and intended base: Closes [Bug]: shipped-runtime UTF-8 guard fails on main - the stride schema asset is read with the host locale codec #6352; intended base main.

Author Declaration

• Written by: model_agent (OpenAI Codex), operating under the human operator's direction and review.
• AI disclosure: this change was drafted with AI assistance at my request, under my direction and review.

Implemented against

• Specification and revision: no written specification; issue [Bug]: shipped-runtime UTF-8 guard fails on main - the stride schema asset is read with the host locale codec #6352 and the guard contract in tests/test_loopx_text_io_utf8.py (revision 64bfb8343 of main) are the basis.
• Criteria:

Criterion (spec clause)	Disposition	Symbol / path	Test or command
Shipped-runtime text reads and writes pin UTF-8 (guard docstring; #4941 / #4338 / #4942 / #4997 class)	implemented	loopx/control_plane/work_items/stride_policy_codec.py:16	uv run --extra test python -m pytest -q tests/test_loopx_text_io_utf8.py
The locale read does not reopen for stride_strategy_options() / normalize_stride_strategy() consumers	implemented	same	guard test; tests/capabilities/test_machine_configuration_goal_defaults.py; tests/control_plane/test_replan_host_context_projection.py

• Self-check before submission: read the guard contract, the guard helper scan, and the codec module; ran the guard before and after, the sibling subprocess-UTF-8 guard, the stride configuration and replan-projection tests, ruff on the changed file, git diff --check, the public/private boundary scan, the semantic-inventory advisory (no new vocabulary), and the risk-selected premerge canary; compared the canary's failing analyzer smokes against the same run on the base revision to separate inherited environment failures. Did not run the full local pytest suite; see Coverage and gaps.

Scope And Continuation

• Completed scope and remaining work: complete within this scope - the single offending site is fixed; no follow-up is required.
• Slice boundary / successor: N/A (self-contained repair; nothing else in the module reads or writes text).

Validation

• Tested revision: cf193cf16623565385d1c3be3e30c0cf2148eb9a
• Run state: finished
• Input classes: public_fixture

Check kind	Result	Public-safe evidence / limitation
static	passed	uv run --extra test python -m ruff check loopx/control_plane/work_items/stride_policy_codec.py: all checks passed
static	passed	scripts/generate_semantic_inventory.py --changed-from HEAD (advisory): no supported new-vocabulary carriers in the diff
static	passed	git diff --check clean; loopx check --scan-path <changed file>: errors=0, warnings=0, public boundary scan clean
unit	passed	Guard before/after: 1 failed, 1 passed on main 64bfb8343 (offender loopx/control_plane/work_items/stride_policy_codec.py:16) -> 2 passed on this head
unit	passed	tests/test_runtime_subprocess_utf8.py, tests/capabilities/test_machine_configuration_goal_defaults.py, tests/control_plane/test_replan_host_context_projection.py: 33 passed
integration	failed	loopx canary premerge --from-git-diff --git-diff-base upstream/main on native Windows: diff hygiene, py_compile and the module-ceiling recollection check passed; four analyzer/canary smokes fail on this host (semantic-vocabulary-drift-smoke.py without npm ci; catalog-run-e2e-smoke.py, premerge-validation-gate-smoke.py, smoke-suite-runner-smoke.py on POSIX-vs-Windows path-separator assertions). All four reproduce identically at the base revision; the vocabulary smoke passes after the documented npm ci --ignore-scripts prerequisite. Inherited, unrelated to this diff
manual	passed	Locale probe on a cp936 host: the unguarded read_text() returns mojibake (round-trip false); encoding="utf-8" round-trips

• Coverage and gaps: the diff is one codec-pinned read; the owning check is the platform-independent AST guard over loopx/**, which is the test this change restores. The full local pytest suite was not run by the author; the required pytest aggregate runs on CI. Four canary analyzer smokes fail identically on the base revision on this Windows host and are inherited rather than caused by this diff (named in the integration row).

Frontend / Visual Evidence

• UI impact: none
• Before: N/A
• After: N/A
• States and viewports shown: N/A (no viewport change)
• Source data: none
• Attention review: N/A (no viewport change)
• Craft review: N/A (no viewport change)

Type of Change

• Bug fix

LoopX Area

• Control plane (goals, todos, quota, scheduler, registry, runtime)

Technical Direction

• Direction / acceptance reference, when applicable: N/A - ordinary repaired-defect maintenance; no roadmap/RFC dependency.

Shared-authority RFC fixture impact

• Production-scale fixture schema: N/A
• Semantic dimensions changed, or reviewed no-impact rationale: N/A - no RFC progress claimed.
• Provider conformance arms run: N/A
• Read-only legacy/file/PostgreSQL three-arm rehearsal (required for promotion, runtime-routing, or compatibility-projection changes): N/A

Boundary Checklist

• Neither the diff nor this PR body/comments/attachments disclose private state, credentials, raw traces or verifier output, internal links, or local machine paths (including .loopx/, .codex/goals/, and live ACTIVE_GOAL_STATE.md).
• I did not duplicate maintainer-owned benchmark work unless a maintainer split out a public issue for it.
• I kept the change scoped to the linked issue/task.
• I completed the visual evidence section for UI changes, or marked UI impact none.
• Every commit includes a DCO Signed-off-by trailer (git commit -s).

[mergify]

This pull request has merge conflicts with main and cannot be merged
until they are resolved. Please rebase or merge the base branch, @JasonBuildAI.

Choose the remote for the base repository, not an out-of-date fork.
For a fork clone, first inspect git remote -v; upstream must point
to https://github.com/loopx-project/loopx.git. If it is absent, add it
with git remote add upstream https://github.com/loopx-project/loopx.git.
Then run:

git fetch upstream
git rebase upstream/main
# Resolve each conflict, git add the resolved files, then git rebase --continue.
git push --force-with-lease origin HEAD

For a same-repository clone whose origin points to
https://github.com/loopx-project/loopx.git, use origin instead of
upstream for fetch/rebase. If you prefer merging the base, use
git merge <base-remote>/main and push normally.

Keep the DCO Signed-off-by trailer on every commit when you rebase.
https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/syncing-a-fork

[JasonBuildAI]

The same one-line fix landed on main independently while this PR was being prepared: 156eee4c9 ("fix(control-plane): reuse frontier counters and pin resource UTF-8", merged with ca01854f4 via #6318) pins encoding="utf-8" on the same read_text() call, and tests/test_loopx_text_io_utf8.py now passes on main (verified 2 passed against b0b2acffb). The remaining delta in this PR is only a line wrap, so it is redundant.

Closing to avoid duplicate work; issue #6352 is resolved by that commit and is closed with a reference. I will not re-open this branch.