INF-1307 drop generated typed clients; clears all GRC warnings

The CLI is fully spec-driven - cmd/twoctl/cli/operations.go walks the
embedded OpenAPI spec at startup and registers a cobra command per
operation. Nothing outside zz_generated.go ever imported the typed
clients, so they were 22k lines of dead code that only existed to feed
goreportcard misspellings (oustanding, occured in upstream specs),
gocyclo violations (CountryCodeEnum.Valid at complexity 145, generated
union Marshal/Unmarshal, etc.), and golint nits we could not fix without
forking oapi-codegen.

Removed:
  - internal/clients/<api>/zz_generated.go (~22k lines)
  - oapi-codegen tool dependency
  - oapi-codegen.yaml configs

Kept:
  - openapi/<api>-api.yaml (vendored upstream)
  - internal/preprocess (3.1 -> 3.0 rewriter)
  - cmd/twoctl/cli/specs/*.processed.yaml (embedded for runtime)

scripts/codegen.sh now only runs the preprocess step and copies the
processed specs into the embed dir.

Local lint sweep across the whole repo (gofmt -s, go vet, ineffassign,
misspell, gocyclo over 15, golint) produces zero output.

Author: brtkwr

docs/regeneration.md

@@ -34,7 +34,7 @@ The `regenerate.yml` workflow uses `GITHUB_TOKEN` for PR creation. No extra secr
 ./scripts/codegen.sh
 ```
 
-That preprocesses the OpenAPI 3.1 specs into 3.0-compatible shape (see [`internal/preprocess`](../internal/preprocess/main.go)), generates the typed Go clients into `internal/clients/<api>/zz_generated.go`, and copies the processed specs into `cmd/twoctl/cli/specs/` so the CLI can embed them.
+That preprocesses the OpenAPI 3.1 specs into 3.0-compatible shape (see [`internal/preprocess`](../internal/preprocess/main.go)) and copies the processed specs into `cmd/twoctl/cli/specs/` for embedding. The CLI parses the embedded spec at startup and walks every operation; no typed Go client code is generated, which keeps the dependency surface small and the Go Report Card clean.
 
 ## Releases
 

go.mod

@@ -2,10 +2,9 @@ module github.com/two-inc/twoctl
 
 go 1.26.3
 
-tool github.com/oapi-codegen/oapi-codegen/v2/cmd/oapi-codegen
-
 require (
-	github.com/oapi-codegen/runtime v1.4.1
+	github.com/getkin/kin-openapi v0.139.0
+	github.com/minio/selfupdate v0.6.0
 	github.com/spf13/cobra v1.10.2
 	github.com/zalando/go-keyring v0.2.8
 	golang.org/x/term v0.43.0
@@ -14,35 +13,27 @@ require (
 
 require (
 	aead.dev/minisign v0.2.0 // indirect
-	github.com/apapsch/go-jsonmerge/v2 v2.0.0 // indirect
 	github.com/danieljoos/wincred v1.2.3 // indirect
-	github.com/dprotaso/go-yit v0.0.0-20220510233725-9ba8df137936 // indirect
-	github.com/fsnotify/fsnotify v1.9.0 // indirect
-	github.com/getkin/kin-openapi v0.139.0 // indirect
+	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
 	github.com/go-openapi/jsonpointer v0.22.4 // indirect
 	github.com/go-openapi/swag/jsonname v0.25.4 // indirect
 	github.com/godbus/dbus/v5 v5.2.2 // indirect
-	github.com/google/uuid v1.6.0 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/josharian/intern v1.0.0 // indirect
+	github.com/kr/pretty v0.3.1 // indirect
 	github.com/mailru/easyjson v0.9.1 // indirect
-	github.com/minio/selfupdate v0.6.0 // indirect
 	github.com/mohae/deepcopy v0.0.0-20170929034955-c48cc78d4826 // indirect
-	github.com/oapi-codegen/oapi-codegen/v2 v2.7.0 // indirect
 	github.com/oasdiff/yaml v0.1.0 // indirect
 	github.com/oasdiff/yaml3 v0.0.13 // indirect
 	github.com/perimeterx/marshmallow v1.1.5 // indirect
+	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
+	github.com/rogpeppe/go-internal v1.13.1 // indirect
 	github.com/santhosh-tekuri/jsonschema/v6 v6.0.2 // indirect
-	github.com/speakeasy-api/jsonpath v0.6.3 // indirect
-	github.com/speakeasy-api/openapi v1.19.2 // indirect
 	github.com/spf13/pflag v1.0.10 // indirect
-	github.com/vmware-labs/yaml-jsonpath v0.3.2 // indirect
+	github.com/ugorji/go/codec v1.2.12 // indirect
 	github.com/woodsbury/decimal128 v1.4.0 // indirect
-	go.yaml.in/yaml/v3 v3.0.4 // indirect
 	golang.org/x/crypto v0.46.0 // indirect
-	golang.org/x/mod v0.33.0 // indirect
-	golang.org/x/sync v0.19.0 // indirect
 	golang.org/x/sys v0.44.0 // indirect
 	golang.org/x/text v0.34.0 // indirect
-	golang.org/x/tools v0.42.0 // indirect
+	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
 )