hrw4u: disallow inbound.url.{} as an operator

[mlibbey]

When one uses inbound.url.{} as an operator, for instance: REMAP {
inbound.url.host = "example.com";
}
hrw4u turns this into set-destination which modifies the outbound URL, making the naming actively misleading.

inbound.url reads from the pristine client URL (CLIENT-URL) which is immutable — ATS provides no mechanism to set it. So, removing this as an operator, but keeping it as a valid condition.

[Copilot]

Pull request overview

This PR updates hrw4u so URL mutations are expressed through outbound.url.* instead of inbound.url.*, aligning the DSL with ATS semantics where inbound.url is read-only client URL state. It mainly adjusts operator/reverse-mapping behavior plus the corresponding fixtures and user docs.

Changes:

• Removed inbound.url.* from the assignment/operator map and kept destination mutations on outbound.url.*.
• Updated reverse-resolution logic so set-destination/rm-destination QUERY decompile back to outbound.url.*.
• Refreshed tests and admin-guide examples to use the new spelling.

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
tools/hrw4u/tests/data/ops/set-destination.input.txt	Updates operator fixture to use outbound.url.*.
tools/hrw4u/tests/data/ops/set-destination.ast.txt	Updates expected AST for the new operator spelling.
tools/hrw4u/tests/data/ops/bad_path.fail.input.txt	Adjusts invalid-suffix failure fixture to target outbound.url.*.
tools/hrw4u/tests/data/ops/bad_path.fail.error.txt	Updates expected error text for the renamed fixture input.
tools/hrw4u/tests/data/examples/rm-query.input.txt	Switches example query removal to outbound.url.query.
tools/hrw4u/tests/data/examples/rm-query.ast.txt	Updates AST expectation for the query-removal example.
tools/hrw4u/tests/data/examples/all-nonsense.input.txt	Rewrites example destination mutations to outbound.url.*.
tools/hrw4u/tests/data/examples/all-nonsense.ast.txt	Updates the large example AST to match the new semantics.
tools/hrw4u/src/tables.py	Removes inbound.url.* as an operator target and changes reverse context defaults to outbound.url.*.
tools/hrw4u/src/hrw_symbols.py	Makes reverse conversion of rm-destination QUERY emit outbound.url.query = "".
tools/hrw4u/src/generators.py	Adjusts URL reverse-context mapping so REMAP also resolves to outbound.url.*.
doc/admin-guide/configuration/hrw4u.en.rst	Documents inbound.url as immutable and updates operator mapping/examples to outbound.url.*.

[mlibbey]

Yeah -- I didn't add a negative test because I'm somewhat expecting that we end up adding something that can modify the inbound url in some manner; which would then have us undo the test.