Graph Editor: "View Selected" should frame the entire selected channel when no keyframes are selected

Problem:

Currently, in the Graph Editor and Drivers Editor, Frame Selected ( graph.view_selected / Numpad . ) only calculates the bounding box based on explicitly selected keyframes .

If a user selects a channel in the left channel list (or focuses on the active curve) but hasn't selected any individual keyframe vertices on the curve:

• Blender falls back to a default view centered around the coordinate baseline (around Y = 0.0).
• If the curve values are high (e.g., Rotation channels in degrees like 90°–360°, large transforms, or custom driver values), the curve is cut off or pushed completely out of the viewport.
• The user is forced to perform extra repetitive steps: press A to select all keyframes, and only then press Numpad . .

Proposed Solution:

Improve the fallback hierarchy of View Selected in the Graph / Drivers Editor:

1. If keyframe vertices are selected --> Frame the bounding box of the selected keyframes (current behavior).
2. If NO keyframes are selected, but one or more channels are selected/active --> Automatically calculate the bounding box and frame the entire curve(s) of the selected/active channel(s) (min/max X and Y of the whole F-Curve).
3. If neither keyframes nor channels are selected --> Fall back to the default origin view ( Y=0 ) or view all.

Benefits:

• Fewer Clicks : Animators and riggers don't have to keep pressing A --> Numpad . every time they switch channels to inspect high-value curves.