Glossary component strings are counted in project/component-list statistics

### Describe the issue

Since version 4.5, glossaries are implemented as regular translation components. This means their strings are included in project-level statistics (translated/untranslated string counts, completion percentage, word counts, etc.).
This is misleading because glossary terms are fundamentally different from regular translation strings — they are terminology references, not translatable content in the traditional sense. Including them in project statistics distorts the real translation progress visible on the project page, component list (/component-list/.../#information), widgets, and API statistics endpoints.
For projects with large glossaries (e.g. thousands of terms), the skew in reported completion percentage can be significant.

### I already tried

- [x] I've read and searched [the documentation](https://docs.weblate.org/).
- [x] I've searched for similar filed issues in this repository.

### Steps to reproduce the behavior

1 Have a project with one or more regular translation components and a glossary component with at least a few hundred terms.
2 Navigate to the project overview page or a component list page (/component-list//#information).
3 Observe the total string count and translation percentage.
4 Compare the numbers with and without glossary terms included — the glossary inflates the "total strings" count and can lower the completion percentage if not all glossary terms are translated in all languages.

### Expected behavior

Glossary components (those with is_glossary: true) should be excluded by default from project-level and component-list statistics, since they represent terminology data — not translation progress.
Ideally, one of the following solutions would be implemented:

- Automatically exclude components flagged as is_glossary from aggregated project statistics.

- Add an optional per-component setting: "Exclude from project statistics" (a checkbox in component settings).

- Clearly document the current behavior and provide a workaround (e.g. via component lists that exclude glossary).

### Screenshots

_No response_

### Exception traceback

```pytb

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### How do you run Weblate?

Docker container

### Weblate versions

_No response_

### Weblate deploy checks

```shell

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### Additional context

_No response_