Migrate module path from kyle/ to mc/ org

All import paths updated from git.wntrmute.dev/kyle/mcias to
git.wntrmute.dev/mc/mcias to match the Gitea organization.
Includes main module and clients/go submodule.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

PROJECT_PLAN.md

@@ -21,7 +21,7 @@ features implemented beyond the original plan scope.
 
 ### Step 0.1: Go module and dependency setup
 **Acceptance criteria:**
-- `go.mod` exists with module path `git.wntrmute.dev/kyle/mcias`
+- `go.mod` exists with module path `git.wntrmute.dev/mc/mcias`
 - Required dependencies declared: `modernc.org/sqlite` (CGo-free SQLite),
   `golang.org/x/crypto` (Argon2, Ed25519 helpers), `github.com/golang-jwt/jwt/v5`,
   `github.com/pelletier/go-toml/v2`, `github.com/google/uuid`,
@@ -543,7 +543,7 @@ implementation notes.
 
 ### Step 9.2: Go client library
 **Acceptance criteria:**
-- `clients/go/` — Go module `git.wntrmute.dev/kyle/mcias/clients/go`
+- `clients/go/` — Go module `git.wntrmute.dev/mc/mcias/clients/go`
 - Package `mciasgoclient` exposes the canonical API surface from Step 9.1
 - Uses `net/http` with `crypto/tls`; custom CA cert supported via `x509.CertPool`
 - Token stored in-memory; `Client.Token()` accessor returns current token