[bsky did 4] Special-case configured bsky DID and URL

[rafaelbsky]

Testing:

1. Checkout this branch.
2. Let's first remove the special-casing and ensure the PDS is proxying to the service endpoint specified on the DID doc:

   diff --git a/packages/dev-env/src/bsky.ts b/packages/dev-env/src/bsky.ts
   index b20191257..bdf8e94a4 100644
   --- a/packages/dev-env/src/bsky.ts
   +++ b/packages/dev-env/src/bsky.ts
   @@ -34,6 +34,8 @@ export class TestBsky {
          signer: serviceKeypair,
        })
    
   +    console.log('bsky DID:', serverDid)
   +
        const endpoint = `http://localhost:${port}`
    
        await plcClient.updateData(serverDid, serviceKeypair, (x) => {
   @@ -43,7 +45,7 @@ export class TestBsky {
          }
          x.services['bsky_appview'] = {
            type: 'BskyAppView',
   -        endpoint,
   +        endpoint: 'http://localhost',
          }
          return x
        })
   diff --git a/packages/pds/src/pipethrough.ts b/packages/pds/src/pipethrough.ts
   index c54cf81ea..eb6a065e4 100644
   --- a/packages/pds/src/pipethrough.ts
   +++ b/packages/pds/src/pipethrough.ts
   @@ -262,12 +262,12 @@ export const parseProxyHeader = async (
      }
    
      // Special case a configured appview, while still proxying correctly any other appview
   -  if (
   -    ctx.cfg.bskyAppView &&
   -    proxyTo === `${ctx.cfg.bskyAppView.did}#bsky_appview`
   -  ) {
   -    return { did, url: ctx.cfg.bskyAppView.url }
   -  }
   +  // if (
   +  //   ctx.cfg.bskyAppView &&
   +  //   proxyTo === `${ctx.cfg.bskyAppView.did}#bsky_appview`
   +  // ) {
   +  //   return { did, url: ctx.cfg.bskyAppView.url }
   +  // }
    
      return { did, url }
    }
   

3. On atproto folder, make run build and make run-dev-env.
4. Copy the bsky DID that was printed in the terminal (added in the patch above).
5. Create a session:

   curl --location 'http://localhost:2583/xrpc/com.atproto.server.createSession' \
   --header 'Content-Type: application/json' \
   --data '{
       "identifier": "alice.test",
       "password": "hunter2"
   }
   '

6. Copy the accessJwt, and together with the DID you copied earlier, do (replacing the 2 placeholders):

   curl --location 'http://localhost:2583/xrpc/app.bsky.actor.getProfile?actor=alice.test' \
   --header 'atproto-proxy: <did>#bsky_appview' \
   --header 'Authorization: Bearer <accessJwt>'

7. This should fail with {"error":"UpstreamFailure","message":"Upstream service unreachable"}. This means it tried to use the endpoint from the DID doc, which as you can see on step 2, was set to http://localhost, which is incorrect (missing the port).
8. Reset all changes, apply this patch, then build and run again. Copy the new DID printed.

   diff --git a/packages/dev-env/src/bsky.ts b/packages/dev-env/src/bsky.ts
   index b20191257..bdf8e94a4 100644
   --- a/packages/dev-env/src/bsky.ts
   +++ b/packages/dev-env/src/bsky.ts
   @@ -34,6 +34,8 @@ export class TestBsky {
          signer: serviceKeypair,
        })
    
   +    console.log('bsky DID:', serverDid)
   +
        const endpoint = `http://localhost:${port}`
    
        await plcClient.updateData(serverDid, serviceKeypair, (x) => {
   @@ -43,7 +45,7 @@ export class TestBsky {
          }
          x.services['bsky_appview'] = {
            type: 'BskyAppView',
   -        endpoint,
   +        endpoint: 'http://localhost',
          }
          return x
        })

9. Run (copy the accessJwt from the result):

   curl --location 'http://localhost:2583/xrpc/com.atproto.server.createSession' \
   --header 'Content-Type: application/json' \
   --data '{
       "identifier": "alice.test",
       "password": "hunter2"
   }
   '

10. Run this (replacing the 2 placeholders with the values copied from the previous 2 steps):

    curl --location 'http://localhost:2583/xrpc/app.bsky.actor.getProfile?actor=alice.test' \
    --header 'atproto-proxy: <did>#bsky_appview' \
    --header 'Authorization: Bearer <accessJwt>'

11. Note how this succeeds. This means that, even though the DID document states the service endpoint as http://localhost, it is using the configured endpoint of http://localhost:2584. So the special-casing for the configured DID is working (it is using the configured URL).