AI configuration previews

ai_config and ai.config inspect local model/role inventory, plan a typed recipe, validate its diff, and explicitly save it. They never call a provider, activate a recipe, change the active session model, or start a workflow. The advisor is off.

The TUI uses /ai-config: ↑/↓ selects a model, p plans, [/] selects a feasible alternative, v validates, and a opens exact-save confirmation. Enter saves; Esc cancels. r refreshes; PgUp/PgDn scroll panels. Below 70 columns, 1/2/3 switches inventory/preview/validation. Plan options can be passed as JSON:

/ai-config plan {"intent":"economical","taskKind":"repair","candidates":[{"role":"main"},{"role":"small"}]}

The CLI uses the same daemon contract, including previews saved to files:

mendcode --dir /tmp/mendcode-data ai-config inspect --json
mendcode --dir /tmp/mendcode-data ai-config plan --input '{"intent":"balanced","taskKind":"repair","candidates":[{"model":"local:main"}]}' --json
mendcode --dir /tmp/mendcode-data ai-config validate --file preview.json --json
mendcode --dir /tmp/mendcode-data ai-config apply --file preview.json --yes --json

For --file, save the plan data object (not the CLI result envelope) as preview.json. Validate/apply accept that preview or a patch with explicit --scope, --target, and --expected-hash. The CLI creates its own causal session after validation. Apply requires explicit --yes; the TUI requires confirmation; agent calls use the engine's write-permission gate. Global tool writes also ask in edits mode. Mixed ai.config operations are excluded from remote read-only access.

Project targets are .mendcode/recipes/<name>.json; global targets are <dataDir>/recipes/<name>.json, only with explicit global scope. Both use the existing recipe format (description, optional version, roles). Target names are lowercase slugs, and files/parents cannot be symlinks. Exact-byte SHA-256 checks reject stale previews. Replacements preserve a byte-exact 0600 backup and atomically rename a 0600 file. Invalid/unavailable choices, malformed existing files, outside targets, and sessions from another project are refused. Unknown fields are rejected rather than removed from an existing recipe.

recipe apply <name> or /model activates a saved recipe separately. Configured variant and effort choices are validated without silently changing them. quality preserves candidate order; economical and balanced order known local tariffs before unknown ones. Pricing comes only from configured budget tariffs; subscription quota remains unknown in USD. The 32K-token estimate is a comparison, not an enforced runtime cap or quality ranking.

Recipes offer only executable single-model role bindings. Cascade and critic execution are configured and started explicitly through /compound, and compaction profiles through /compaction. They are separate runtime contracts, never activated by saving a recipe. The inspector reports v2's actual autocompact threshold; the advisor remains off.