[Bugfix][Muse Glimmer] Keep tool-call arguments that the ATEM parser …

[honziik]

Purpose

Two ways a tool call reaches the client without its arguments on this branch.
In each the client answers "invalid arguments" and the model spends a round
rediscovering what it already said. Found while serving Muse-Glimmer-30B from
this branch to an agentic client that reads and writes files.

1. A parameter declared type: string is JSON-decoded. _decode_value runs
   on every value, so a client writing a JSONL line to a file gets
   SchemaError(Expected string, got {...} at ["content"]) and the write is
   rejected. Declared string parameters are now left as strings; everything else
   decodes as before.

2. The model sometimes swallows the opening <atem:parameter> tag and glues
   its name onto the invoke name, leaving the value as the body of the block:

   <atem:invoke name="read.filePath">/tmp/norm.txt</atem:parameter>
   </atem:invoke>

   No <atem:parameter> pair matches, so args comes out empty and the client
   reports Missing key at ["filePath"]. The value is recovered from the body
   when the emitted name carried the parameter name.

The second shape also needs read.filePath to bind to read, so
_normalize_name collapses a head that is itself registered, not just the
doubled head == tail form. Suffix matching stays refused - in both shapes the
model actually emits, the tool is named in the head - so
test_unregistered_namespace_is_preserved keeps passing unchanged.

Test Plan

tests/tool_use/test_muse_glimmer.py - the existing suite plus four new tests:
the two malformed shapes, and the two cases that must NOT change (an undeclared
parameter still decodes; a parameterless namespaced call is left alone).

Test Result

test	before	after
test_string_parameter_is_not_json_decoded	fail	pass
test_swallowed_parameter_tag_recovers_argument	fail	pass
test_undeclared_parameter_still_decodes	pass	pass
test_parameterless_namespaced_call_is_left_alone	pass	pass
test_unregistered_namespace_is_preserved and the other name/decoding tests	pass	pass

Rebased onto the current head of this branch; the two new tests fail against it
and pass with this change, and nothing that passed before regresses.

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