feat(hyperguild): README + Taskfile integration

Adds cmd/hyperguild/README.md (subcommands, env vars, install path)
and three Taskfile targets:

  task hyperguild:dev     — go run from source
  task hyperguild:build   — build into ./bin/hyperguild
  task hyperguild:install — go install into $GOBIN

Concludes Plan 4 of the hyperguild migration. The binary replaces
the supervisor's tier MCP and surfaces brain HTTP REST access plus
mode bootstrap to shell pipelines and ad-hoc agent prompts.

Taskfile.yml

@@ -39,6 +39,22 @@ tasks:
     cmds:
       - go run ./cmd/supervisor
 
+  hyperguild:dev:
+    desc: Run hyperguild CLI from source (e.g. task hyperguild:dev -- tier)
+    cmds:
+      - go run ./cmd/hyperguild {{.CLI_ARGS}}
+
+  hyperguild:build:
+    desc: Build the hyperguild binary into ./bin/hyperguild
+    cmds:
+      - mkdir -p bin
+      - go build -o bin/hyperguild ./cmd/hyperguild
+
+  hyperguild:install:
+    desc: Install hyperguild into $GOBIN
+    cmds:
+      - go install ./cmd/hyperguild
+
   ingestion:dev:
     desc: Run ingestion server in development mode
     dir: ingestion