docs(agent-context): make schema-apply doctrine per-stack (#192)

agent-context/templates/always-on.md.mustache

@@ -10,8 +10,8 @@ spine; generated code is the disposable artifact. Regenerate with `{{codegenComm
 
 ## Principles
 - **Adopting onto existing code? Metadata FOLLOWS the code.** On a migration (existing working code / live DB), author metadata + tune codegen to *reproduce* what the code already is — native types (`field.uuid` when the code uses `UUID`, not `field.string`), names, nullability — so regen changes as little existing code as possible. The only existing code that should change is the hand-written layer codegen replaces; ask when a modeling choice is ambiguous. (Greenfield: model-first, below.)
-- Pattern-derivable from metadata = codegen, never hand-write — FKs, CRUD, validators, finders, and the database schema and migrations. The schema is a disposable, generated artifact: change the metadata and regenerate, never hand-write SQL.
-- The **live database** is a derived artifact too — never hand-apply a schema change to a running DB (ad-hoc `psql`/console `ALTER`/`CREATE`/`DROP`), not even to preview a column or unblock a boot. Apply schema only through `meta migrate` (metadata → DDL). A hand-applied change drifts the live DB from the metadata + migration history and collides at the next migrate/boot ("column already exists") — a state no migration can reproduce. Run `meta verify --db` after any DB-touching work to catch that drift early.
+- Pattern-derivable from metadata = codegen, never hand-write — FKs, CRUD, validators, finders, and the database schema and migrations. The schema is a disposable, generated artifact: change the metadata and regenerate. Don't hand-write divergent SQL; where a stack owns its own migration files (Flyway/Liquibase), they must **match** the generated schema, not invent it.
+- The **live database** is a derived artifact too — never hand-apply a schema change to a running DB (ad-hoc `psql`/console `ALTER`/`CREATE`/`DROP`), not even to preview a column or unblock a boot. Drive every schema change from the metadata, never ad-hoc: on the Node/TS-owned migrate stack that is `meta migrate` (metadata → DDL, ADR-0015); on a JVM stack whose migration tool `meta migrate` does not emit for (e.g. **Flyway**/Liquibase) author the migration to match the generated schema (the source of truth). A hand-applied ad-hoc change drifts the live DB from the metadata + migration history and collides at the next migrate/boot ("column already exists") — a state no migration can reproduce. Run `meta verify --db` after any DB-touching work to catch that drift early.
 - Never hand-edit generated files — change the metadata and regenerate (three-way merge preserves hand-written regions).
 - Use the generated constants for any string that names metadata.
 - The loaded metadata model is READ-ONLY — never inject nodes or mutate the tree at load time (no "enrich the model on load" hooks). Need an extra field/column? Author it in the metadata, or derive it during codegen (read the metadata, emit output). Mutating the loaded model makes it diverge from what's declared — a bad practice reserved for very rare cases.

fixtures/agent-context-conformance/java-kotlin-react-tanstack/expected/.metaobjects/AGENTS.md

@@ -10,8 +10,8 @@ spine; generated code is the disposable artifact. Regenerate with `mvn metaobjec
 
 ## Principles
 - **Adopting onto existing code? Metadata FOLLOWS the code.** On a migration (existing working code / live DB), author metadata + tune codegen to *reproduce* what the code already is — native types (`field.uuid` when the code uses `UUID`, not `field.string`), names, nullability — so regen changes as little existing code as possible. The only existing code that should change is the hand-written layer codegen replaces; ask when a modeling choice is ambiguous. (Greenfield: model-first, below.)
-- Pattern-derivable from metadata = codegen, never hand-write — FKs, CRUD, validators, finders, and the database schema and migrations. The schema is a disposable, generated artifact: change the metadata and regenerate, never hand-write SQL.
-- The **live database** is a derived artifact too — never hand-apply a schema change to a running DB (ad-hoc `psql`/console `ALTER`/`CREATE`/`DROP`), not even to preview a column or unblock a boot. Apply schema only through `meta migrate` (metadata → DDL). A hand-applied change drifts the live DB from the metadata + migration history and collides at the next migrate/boot ("column already exists") — a state no migration can reproduce. Run `meta verify --db` after any DB-touching work to catch that drift early.
+- Pattern-derivable from metadata = codegen, never hand-write — FKs, CRUD, validators, finders, and the database schema and migrations. The schema is a disposable, generated artifact: change the metadata and regenerate. Don't hand-write divergent SQL; where a stack owns its own migration files (Flyway/Liquibase), they must **match** the generated schema, not invent it.
+- The **live database** is a derived artifact too — never hand-apply a schema change to a running DB (ad-hoc `psql`/console `ALTER`/`CREATE`/`DROP`), not even to preview a column or unblock a boot. Drive every schema change from the metadata, never ad-hoc: on the Node/TS-owned migrate stack that is `meta migrate` (metadata → DDL, ADR-0015); on a JVM stack whose migration tool `meta migrate` does not emit for (e.g. **Flyway**/Liquibase) author the migration to match the generated schema (the source of truth). A hand-applied ad-hoc change drifts the live DB from the metadata + migration history and collides at the next migrate/boot ("column already exists") — a state no migration can reproduce. Run `meta verify --db` after any DB-touching work to catch that drift early.
 - Never hand-edit generated files — change the metadata and regenerate (three-way merge preserves hand-written regions).
 - Use the generated constants for any string that names metadata.
 - The loaded metadata model is READ-ONLY — never inject nodes or mutate the tree at load time (no "enrich the model on load" hooks). Need an extra field/column? Author it in the metadata, or derive it during codegen (read the metadata, emit output). Mutating the loaded model makes it diverge from what's declared — a bad practice reserved for very rare cases.

fixtures/agent-context-conformance/java-kotlin-react-tanstack/expected/.metaobjects/CLAUDE.md

@@ -10,8 +10,8 @@ spine; generated code is the disposable artifact. Regenerate with `mvn metaobjec
 
 ## Principles
 - **Adopting onto existing code? Metadata FOLLOWS the code.** On a migration (existing working code / live DB), author metadata + tune codegen to *reproduce* what the code already is — native types (`field.uuid` when the code uses `UUID`, not `field.string`), names, nullability — so regen changes as little existing code as possible. The only existing code that should change is the hand-written layer codegen replaces; ask when a modeling choice is ambiguous. (Greenfield: model-first, below.)
-- Pattern-derivable from metadata = codegen, never hand-write — FKs, CRUD, validators, finders, and the database schema and migrations. The schema is a disposable, generated artifact: change the metadata and regenerate, never hand-write SQL.
-- The **live database** is a derived artifact too — never hand-apply a schema change to a running DB (ad-hoc `psql`/console `ALTER`/`CREATE`/`DROP`), not even to preview a column or unblock a boot. Apply schema only through `meta migrate` (metadata → DDL). A hand-applied change drifts the live DB from the metadata + migration history and collides at the next migrate/boot ("column already exists") — a state no migration can reproduce. Run `meta verify --db` after any DB-touching work to catch that drift early.
+- Pattern-derivable from metadata = codegen, never hand-write — FKs, CRUD, validators, finders, and the database schema and migrations. The schema is a disposable, generated artifact: change the metadata and regenerate. Don't hand-write divergent SQL; where a stack owns its own migration files (Flyway/Liquibase), they must **match** the generated schema, not invent it.
+- The **live database** is a derived artifact too — never hand-apply a schema change to a running DB (ad-hoc `psql`/console `ALTER`/`CREATE`/`DROP`), not even to preview a column or unblock a boot. Drive every schema change from the metadata, never ad-hoc: on the Node/TS-owned migrate stack that is `meta migrate` (metadata → DDL, ADR-0015); on a JVM stack whose migration tool `meta migrate` does not emit for (e.g. **Flyway**/Liquibase) author the migration to match the generated schema (the source of truth). A hand-applied ad-hoc change drifts the live DB from the metadata + migration history and collides at the next migrate/boot ("column already exists") — a state no migration can reproduce. Run `meta verify --db` after any DB-touching work to catch that drift early.
 - Never hand-edit generated files — change the metadata and regenerate (three-way merge preserves hand-written regions).
 - Use the generated constants for any string that names metadata.
 - The loaded metadata model is READ-ONLY — never inject nodes or mutate the tree at load time (no "enrich the model on load" hooks). Need an extra field/column? Author it in the metadata, or derive it during codegen (read the metadata, emit output). Mutating the loaded model makes it diverge from what's declared — a bad practice reserved for very rare cases.

fixtures/agent-context-conformance/java-react/expected/.metaobjects/AGENTS.md

@@ -10,8 +10,8 @@ spine; generated code is the disposable artifact. Regenerate with `mvn metaobjec
 
 ## Principles
 - **Adopting onto existing code? Metadata FOLLOWS the code.** On a migration (existing working code / live DB), author metadata + tune codegen to *reproduce* what the code already is — native types (`field.uuid` when the code uses `UUID`, not `field.string`), names, nullability — so regen changes as little existing code as possible. The only existing code that should change is the hand-written layer codegen replaces; ask when a modeling choice is ambiguous. (Greenfield: model-first, below.)
-- Pattern-derivable from metadata = codegen, never hand-write — FKs, CRUD, validators, finders, and the database schema and migrations. The schema is a disposable, generated artifact: change the metadata and regenerate, never hand-write SQL.
-- The **live database** is a derived artifact too — never hand-apply a schema change to a running DB (ad-hoc `psql`/console `ALTER`/`CREATE`/`DROP`), not even to preview a column or unblock a boot. Apply schema only through `meta migrate` (metadata → DDL). A hand-applied change drifts the live DB from the metadata + migration history and collides at the next migrate/boot ("column already exists") — a state no migration can reproduce. Run `meta verify --db` after any DB-touching work to catch that drift early.
+- Pattern-derivable from metadata = codegen, never hand-write — FKs, CRUD, validators, finders, and the database schema and migrations. The schema is a disposable, generated artifact: change the metadata and regenerate. Don't hand-write divergent SQL; where a stack owns its own migration files (Flyway/Liquibase), they must **match** the generated schema, not invent it.
+- The **live database** is a derived artifact too — never hand-apply a schema change to a running DB (ad-hoc `psql`/console `ALTER`/`CREATE`/`DROP`), not even to preview a column or unblock a boot. Drive every schema change from the metadata, never ad-hoc: on the Node/TS-owned migrate stack that is `meta migrate` (metadata → DDL, ADR-0015); on a JVM stack whose migration tool `meta migrate` does not emit for (e.g. **Flyway**/Liquibase) author the migration to match the generated schema (the source of truth). A hand-applied ad-hoc change drifts the live DB from the metadata + migration history and collides at the next migrate/boot ("column already exists") — a state no migration can reproduce. Run `meta verify --db` after any DB-touching work to catch that drift early.
 - Never hand-edit generated files — change the metadata and regenerate (three-way merge preserves hand-written regions).
 - Use the generated constants for any string that names metadata.
 - The loaded metadata model is READ-ONLY — never inject nodes or mutate the tree at load time (no "enrich the model on load" hooks). Need an extra field/column? Author it in the metadata, or derive it during codegen (read the metadata, emit output). Mutating the loaded model makes it diverge from what's declared — a bad practice reserved for very rare cases.

fixtures/agent-context-conformance/java-react/expected/.metaobjects/CLAUDE.md

@@ -10,8 +10,8 @@ spine; generated code is the disposable artifact. Regenerate with `mvn metaobjec
 
 ## Principles
 - **Adopting onto existing code? Metadata FOLLOWS the code.** On a migration (existing working code / live DB), author metadata + tune codegen to *reproduce* what the code already is — native types (`field.uuid` when the code uses `UUID`, not `field.string`), names, nullability — so regen changes as little existing code as possible. The only existing code that should change is the hand-written layer codegen replaces; ask when a modeling choice is ambiguous. (Greenfield: model-first, below.)
-- Pattern-derivable from metadata = codegen, never hand-write — FKs, CRUD, validators, finders, and the database schema and migrations. The schema is a disposable, generated artifact: change the metadata and regenerate, never hand-write SQL.
-- The **live database** is a derived artifact too — never hand-apply a schema change to a running DB (ad-hoc `psql`/console `ALTER`/`CREATE`/`DROP`), not even to preview a column or unblock a boot. Apply schema only through `meta migrate` (metadata → DDL). A hand-applied change drifts the live DB from the metadata + migration history and collides at the next migrate/boot ("column already exists") — a state no migration can reproduce. Run `meta verify --db` after any DB-touching work to catch that drift early.
+- Pattern-derivable from metadata = codegen, never hand-write — FKs, CRUD, validators, finders, and the database schema and migrations. The schema is a disposable, generated artifact: change the metadata and regenerate. Don't hand-write divergent SQL; where a stack owns its own migration files (Flyway/Liquibase), they must **match** the generated schema, not invent it.
+- The **live database** is a derived artifact too — never hand-apply a schema change to a running DB (ad-hoc `psql`/console `ALTER`/`CREATE`/`DROP`), not even to preview a column or unblock a boot. Drive every schema change from the metadata, never ad-hoc: on the Node/TS-owned migrate stack that is `meta migrate` (metadata → DDL, ADR-0015); on a JVM stack whose migration tool `meta migrate` does not emit for (e.g. **Flyway**/Liquibase) author the migration to match the generated schema (the source of truth). A hand-applied ad-hoc change drifts the live DB from the metadata + migration history and collides at the next migrate/boot ("column already exists") — a state no migration can reproduce. Run `meta verify --db` after any DB-touching work to catch that drift early.
 - Never hand-edit generated files — change the metadata and regenerate (three-way merge preserves hand-written regions).
 - Use the generated constants for any string that names metadata.
 - The loaded metadata model is READ-ONLY — never inject nodes or mutate the tree at load time (no "enrich the model on load" hooks). Need an extra field/column? Author it in the metadata, or derive it during codegen (read the metadata, emit output). Mutating the loaded model makes it diverge from what's declared — a bad practice reserved for very rare cases.

fixtures/agent-context-conformance/python/expected/.metaobjects/AGENTS.md

@@ -10,8 +10,8 @@ spine; generated code is the disposable artifact. Regenerate with `metaobjects g
 
 ## Principles
 - **Adopting onto existing code? Metadata FOLLOWS the code.** On a migration (existing working code / live DB), author metadata + tune codegen to *reproduce* what the code already is — native types (`field.uuid` when the code uses `UUID`, not `field.string`), names, nullability — so regen changes as little existing code as possible. The only existing code that should change is the hand-written layer codegen replaces; ask when a modeling choice is ambiguous. (Greenfield: model-first, below.)
-- Pattern-derivable from metadata = codegen, never hand-write — FKs, CRUD, validators, finders, and the database schema and migrations. The schema is a disposable, generated artifact: change the metadata and regenerate, never hand-write SQL.
-- The **live database** is a derived artifact too — never hand-apply a schema change to a running DB (ad-hoc `psql`/console `ALTER`/`CREATE`/`DROP`), not even to preview a column or unblock a boot. Apply schema only through `meta migrate` (metadata → DDL). A hand-applied change drifts the live DB from the metadata + migration history and collides at the next migrate/boot ("column already exists") — a state no migration can reproduce. Run `meta verify --db` after any DB-touching work to catch that drift early.
+- Pattern-derivable from metadata = codegen, never hand-write — FKs, CRUD, validators, finders, and the database schema and migrations. The schema is a disposable, generated artifact: change the metadata and regenerate. Don't hand-write divergent SQL; where a stack owns its own migration files (Flyway/Liquibase), they must **match** the generated schema, not invent it.
+- The **live database** is a derived artifact too — never hand-apply a schema change to a running DB (ad-hoc `psql`/console `ALTER`/`CREATE`/`DROP`), not even to preview a column or unblock a boot. Drive every schema change from the metadata, never ad-hoc: on the Node/TS-owned migrate stack that is `meta migrate` (metadata → DDL, ADR-0015); on a JVM stack whose migration tool `meta migrate` does not emit for (e.g. **Flyway**/Liquibase) author the migration to match the generated schema (the source of truth). A hand-applied ad-hoc change drifts the live DB from the metadata + migration history and collides at the next migrate/boot ("column already exists") — a state no migration can reproduce. Run `meta verify --db` after any DB-touching work to catch that drift early.
 - Never hand-edit generated files — change the metadata and regenerate (three-way merge preserves hand-written regions).
 - Use the generated constants for any string that names metadata.
 - The loaded metadata model is READ-ONLY — never inject nodes or mutate the tree at load time (no "enrich the model on load" hooks). Need an extra field/column? Author it in the metadata, or derive it during codegen (read the metadata, emit output). Mutating the loaded model makes it diverge from what's declared — a bad practice reserved for very rare cases.