dotfiles/.config/dot/.claude/tasks/0002-kde-schema-backed-apply.md

spec, blocked-by

spec	blocked-by
dot-kde	0001-kde-schema-backed-save

What to build

Implement dot kde apply for schema-backed settings: read every entry in the manifest and write its declared value onto the live system via kwriteconfig6. Re-running it against an already-applied system must be a no-op with no unintended side effects — this is the idempotence the feature depends on for safe re-runs after a KDE update or on a freshly built machine. Add dot kde apply help, following the project's check-for-help-before-argparse convention.

Add a README row for dot kde apply.

Acceptance criteria

• dot kde apply pushes every manifest entry's declared value onto the live system via kwriteconfig6
• Re-running dot kde apply against a system already matching the manifest changes nothing (idempotent)
• dot kde apply help prints usage without writing anything
• Tests run against a scratch $HOME, exercising apply over a manifest with schema-backed entries, verifying resulting rc-file contents and idempotence on a second run
• README has a row for dot kde apply

Implementation Notes

• File layout mirrors save's: write_live_value (the kwriteconfig6 counterpart to read_live_value) and apply_one (mirroring save_one's parse_identifier → resolve_mechanism → schema-only gate) added to commands/kde/kde.py; cmd_apply mirrors cmd_save's help/argument/error-handling scaffold. kde.fish gained an apply dispatch case above save.
• apply takes no arguments (unlike save, which supports an optional identifier) — the task only specifies pushing the whole manifest, and the parent spec's apply user story has no per-identifier mode, so dot kde apply <extra-arg> is rejected as misuse rather than silently ignored.
• write_live_value passes the value positionally after a -- separator (kwriteconfig6 --file ... --group ... --key ... -- <value>) rather than via a --value flag, since kwriteconfig6 takes the value as a mandatory positional argument, not a flag; -- guards against a value that itself looks like an option.
• Non-schema (shortcuts/freeform) manifest entries are rejected with the same "not yet supported" error save_one already raises for those mechanisms, kept out of scope per this task's title ("...apply for schema-backed settings"); those mechanisms are added in later tasks (0004, 0005) without needing to restructure cmd_apply.
• /review-uncommitted flagged two baseline duplication smells (apply_one/cmd_apply mirroring save_one/cmd_save's shape) and one observation (a failing entry mid-manifest halts apply immediately, leaving earlier writes already applied — a partial-apply state, untested either way). Left as-is: the duplication mirrors an already-established local convention from task 0001 rather than introducing a new one, and the partial-apply behavior is consistent with cmd_save's pre-existing control flow, not a new risk introduced by this task.