fix(config): redirect misplaced nested keys to the other config with a scope note

[worktrunk-bot]

Addresses @max-sixty's request in #3469: surface a note when a config key only lives in the other config file, and reference project-specific user config when the destination is user config.

Problem

When @KieranP put [list] columns / [list.custom-columns] in project config (.config/wt.toml), the warning read a bare unknown field list.columns, giving no hint that these are user-config display settings. Nested-key redirection only fired for the hard-coded commit.generation leaves, so every other misplaced nested key fell through to "unknown field".

Change

• Generalize nested-key redirection. A nested key that's schema-unknown in the loaded config but valid in the other config type now reports belongs in <other> config instead of unknown field. This is decided by walking the other config's own unknown tree for the same content — a key valid there simply never appears, so its absence is the signal. The existing hard-coded commit.generation redirect stays as a fast-path that still fires even when the other-config analysis is unreliable.
• Reference project-specific user config. When the destination is user config, the warning appends ; to scope it to this repo, add it under [projects."<id>"] in user config — the [projects."<id>"] table is exactly how you keep a personal setting on one repo, which is what reaching for project config usually means.

Both the load-time warning and wt config show share the classification and the note.

Before / after

# Before
▲ Project config has unknown field list.columns (will be ignored)

# After
▲ Project config has key list.columns which belongs in user config (will be ignored); to scope it to this repo, add it under [projects."<id>"] in user config

A key that's genuinely unknown in both configs (a typo like list.nonsense-typo) still reads unknown field, and the reverse direction (list.url — project-only — placed in user config) redirects to project config with no scope note.

Tests

• New unit tests in src/config/deprecation.rs: generalized nested redirect for list.columns/list.full, typo-stays-unknown, reverse-direction redirect, and the scope note fires for user-config destinations only.
• Updated the config_show_suggests_user_config_for_commit_generation snapshot — the commit.generation.command redirect now consistently carries the note.
• cargo clippy --all-targets clean; full lib + integration suites pass (two unrelated failures locally are network-egress / file-permission sandbox artifacts, not touched by this change).

[worktrunk-bot]

Reviewed the generalized nested-key redirection. The OtherStatus lockstep walk is a clean way to answer "valid in the other config?" — traced it through the shared-section (list.columns → user), typo-stays-unknown, whole-section-unknown, and reverse-direction cases and it classifies each correctly. Unit tests pass locally (config::unknown_tree + config::deprecation, 174 passed). One accuracy gap and one minor cleanup:

The scope note is misdirecting for two top-level user-only keys. with_scope_note is now applied unconditionally to TopLevelWrongConfig as well as NestedWrongConfig (format_load_warning in src/config/deprecation.rs, format_show_warning in src/commands/config/show.rs), and scope_to_repo_note fires for any "user config" destination. But the note tells the user to add the key under [projects."<id>"], and UserProjectOverrides (the schema for that table, in src/config/user/sections.rs) only carries worktree-path, list, commit, merge, remove, switch, step, aliases, approved-commands, and hooks. The two top-level scalar user keys — skip-shell-integration-prompt and skip-commit-generation-prompt — aren't fields there. So putting either in project config now yields:

▲ Project config has key skip-shell-integration-prompt which belongs in user config (will be ignored); to scope it to this repo, add it under [projects."<id>"] in user config

…and following that advice produces a fresh unknown field skip-shell-integration-prompt under [projects."<id>"] — plus these two are global first-run flags with no per-repo semantics to begin with. Every section-based redirect (list.*, commit.generation.*, merge.*, …) and worktree-path is genuinely per-project-overridable, so the note is correct for those; the gap is just these two scalars. Since the note only carries other_description, gating it correctly means threading through whether the specific key is a UserProjectOverrides field (or, more cheaply, only appending it on the NestedWrongConfig arm, since the two problem keys are top-level — at the cost of dropping the correct note for a misplaced top-level worktree-path). Flagging for your call rather than pushing, since it's a design tradeoff, not a mechanical fix.

Minor: with_scope_note is duplicated verbatim. The helper is byte-identical in src/config/deprecation.rs and src/commands/config/show.rs (only the path to scope_to_repo_note differs). Since scope_to_repo_note was already made pub and re-exported through src/config/mod.rs for exactly this sharing, the wrapper could be exported alongside it and called from show.rs, keeping the color-print caveat ("note is plain text so [projects."<id>"] isn't parsed as markup") attached to a single definition.

[worktrunk-bot]

Addressed both points in 088eb45.

Scope-note accuracy gap. Took the accurate option rather than the cheaper NestedWrongConfig-only gate — the note now fires only when the misplaced key's top-level segment is an actual [projects."<id>"] field. scope_to_repo_note(other_description, key) gains the key and checks is_user_project_override_key(top_level) (derived from the UserProjectOverrides schema via schema_top_level_keys). This keeps the note for every genuinely per-project-overridable redirect — list.*, commit.generation.*, merge.*, and top-level worktree-path — while dropping it for the two root-only first-run scalars.

Verified end-to-end against a project .config/wt.toml:

▲ Key skip-shell-integration-prompt belongs in user config (will be ignored)
▲ Key list.columns belongs in user config (will be ignored); to scope it to this repo, add it under [projects."<id>"] in user config

Duplicated with_scope_note. Consolidated into one exported definition in src/config/deprecation.rs (re-exported through src/config/mod.rs); show.rs now calls worktrunk::config::with_scope_note, so the color-print caveat lives in a single place.

Also corrected the skip-shell-integration-prompt inline snapshot in src/commands/config/mod.rs — a concurrent commit (cacbefc) had updated it to carry the note; with the gap fixed it correctly reads without one. The commit.generation.command snapshots keep the note (commit is a valid override). New unit coverage asserts the note fires for list.columns/worktree-path and stays absent for both skip-*-prompt scalars.