Remove stale cchost mentions across tests, samples, schema, and host config

[Copilot]

The cchost binary was removed in 7.x (each app is now its own executable), but stale references remained throughout the tree.

Tests / infra (Python)

• Replace # Set to cchost default value comments with # Set to node default value in tests/infra/{runner,piccolo_driver}.py, tests/historical_query_{perf,cache}.py, tests/lts_compatibility.py.
• Update --binary-dir help text in tests/infra/e2e_args.py.
• Remove the CCFRemote.BIN = "" class attribute and require the binary name on construction via a new binary_name kwarg. For major_version >= 7 (or unspecified) the binary is enclave_file; for major_version < 7, binary_name is asserted and resolved via build_bin_path. infra.node.Node passes binary_name="cchost" for pre-7 nodes.

Host config schema

• Rename doc/host_config_schema/cchost_config.json → host_config.json; update CMakeLists.txt and doc/conf.py.
• Rename C++ struct host::CCHostConfig → host::HostConfig (only used in src/host/configuration.h and src/host/run.cpp).

samples/minimal_ccf

• Replace the obsolete mv .../bin/cchost /usr/bin/cchost step in the runtime Dockerfile with a mv .../bin/js_generic /usr/bin/js_generic step, with a comment noting js_generic is a sample binary intended to be replaced when adapting the image.
• Replace the cchost invocation in run_app.sh with js_generic.
• Rename cchost_config_virtual_js.json → config_virtual_js.json.

Formatting

• Re-ran scripts/cmake-format-checks.sh -f to fix CMakeLists.txt formatting flagged by CI (collapsed the file(READ ...) call onto a single line).

Intentionally retained

• CHANGELOG.md historical entries.
• The inline comment in tests/infra/remote.py __init__ explaining the 7.x binary consolidation (kept per review feedback).

[Copilot]

Just as a heads up, I was blocked by some firewall rules while working on your feedback. Expand below for details.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• astral.sh
  • Triggering command: /usr/bin/curl curl -LsSf REDACTED (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)