fix(deps): migrate mcp-chassis to git.d-ma.be path — unblock CD build (#74)

The image build's `go mod download` failed on the stale
gitea.d-ma.be/mathias/mcp-chassis import (the gitea→git rename; the server no
longer serves a matching go-import meta tag). This is the latent #74 breakage
flagged for gitea-mcp, triggered by the first clean rebuild since the rename
(the #42 push). Point at git.d-ma.be/mathias/mcp-chassis v0.2.0 + go mod tidy.

Unblocks deploying the #42 create_project_from_template fix. gitea-mcp's own
module path stays gitea.d-ma.be (main module, not fetched — separate cleanup).
Refs #74, #42.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

go.mod

@@ -3,13 +3,12 @@ module gitea.d-ma.be/mathias/gitea-mcp
 go 1.26.2
 
 require (
+	git.d-ma.be/mathias/mcp-chassis v0.2.0
 	github.com/hashicorp/golang-lru/v2 v2.0.7
-	github.com/lestrrat-go/jwx/v2 v2.1.6
 	github.com/stretchr/testify v1.11.1
 )
 
 require (
-	gitea.d-ma.be/mathias/mcp-chassis v0.1.0 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.4.0 // indirect
 	github.com/goccy/go-json v0.10.3 // indirect
@@ -17,6 +16,7 @@ require (
 	github.com/lestrrat-go/httpcc v1.0.1 // indirect
 	github.com/lestrrat-go/httprc v1.0.6 // indirect
 	github.com/lestrrat-go/iter v1.0.2 // indirect
+	github.com/lestrrat-go/jwx/v2 v2.1.6 // indirect
 	github.com/lestrrat-go/option v1.0.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/segmentio/asm v1.2.0 // indirect