Feat/all in one

[jlee-kitware]

Per-conversation model settings. Model choice was already per-conversation but the settings driving it weren't, so temperature, max_tokens and retry_attempts were global and tuning one conversation retuned all of them. The split was already misfiring: temperature_supported travelled with the session while temperature didn't, so a reasoning model clamped temperature to 1 everywhere and switching back left it stuck. These now travel with the conversation, and their settings surface moves from the global dialog to a control beside the model picker. What's left in the dialog is install-wide and now persists back to config.yml. Also fixes the clamp never releasing and adds a provider env-var fallback for api_token.

Bulk conversation actions. Multi-select in the Recents drawer for pin/unpin/export/delete. Pin and unpin are separate actions since a mixed selection has nothing coherent to toggle to. Export writes one file per conversation so results re-import through the existing path.

VTK call-chain completion. jedi can't infer through VTK's C-extension methods, so tetra.GetPointIds().SetId had no hover and zero completions. Falls back to walking the chain via docstring annotations; completion after GetPointIds(). goes from 0 to 75 entries.

Testing: ruff clean, mypy clean, 104 passing. New tests/test_completion_chain.py. Two commits fix breakage inherited from #40: mypy union-attr errors in code_executor.py, and the test_code_history suite (stale fixture, plus one test asserting undo/redo re-render behaviour that was intentionally removed).

[vicentebolea]

Looks good but I am getting the following errors:

In the console when invoking a prompt and the prompt doesnt execute:

Error generating code: int() argument must be a string, a bytes-like object or a real number, not 'NoneType'

A stdout in the terminal

 JS Error => TypeError: can't access property "replace", local_base_url is undefined
 JS Error => TypeError: can't access property "replace", local_base_url is undefined
 JS Error => TypeError: can't access property "replace", local_base_url is undefined
 JS Error => TypeError: can't access property "replace", local_base_url is undefined
 JS Error => TypeError: can't access property "replace", local_base_url is undefined
 JS Error => TypeError: can't access property "replace", local_base_url is undefined
 JS Error => TypeError: can't access property "replace", local_base_url is undefined
 JS Error => TypeError: can't access property "replace", local_base_url is undefined
 JS Error => TypeError: can't access property "replace", local_base_url is undefined
 JS Error => TypeError: can't access property "replace", local_base_url is undefined
 JS Error => TypeError: can't access property "replace", local_base_url is undefined
 JS Error => TypeError: can't access property "replace", local_base_url is undefined
 JS Error => TypeError: can't access property "replace", local_base_url is undefined
 JS Error => TypeError: can't access property "replace", local_base_url is undefined
 JS Error => TypeError: can't access property "replace", local_base_url is undefined
 JS Error => TypeError: can't access property "replace", local_base_url is undefined
 JS Error => TypeError: can't access property "replace", local_base_url is undefined
 JS Error => TypeError: can't access property "replace", local_base_url is undefined
 JS Error => TypeError: can't access property "replace", local_base_url is undefined

A small UI suggestion is to enlarge the per-chat options: