chore: extract hardcoded URL placeholders into shared constants

[andrewholzbach]

Description

Fixes #138

Changes

• Replaced hardcoded placeholder strings in ModelTab and SearchTab with values read directly from the config prop (config.inference.ollama_url, config.search.searxng_url, config.search.reader_url)

Checklist

• Tests added or updated for all changed code
• bun run test:all:coverage passes with 100% coverage
• bun run validate-build passes with zero warnings and zero errors
• Commit message follows Conventional Commits (feat:, fix:, etc.) so the changelog is generated automatically

[quiet-node]

Hey, thanks for opening this PR!

The CI runs are failing due to a transient GitHub Actions git fetch error, the runners couldn't check out the branch, so none of the tests or build steps actually ran. No issues with your code.

I'll be re-running the jobs periodically until they go through cleanly.

[quiet-node]

Looks like DEFAULT_OLLAMA_URL, DEFAULT_SEARXNG_URL, and DEFAULT_READER_URL are already declared in src-tauri/src/config/defaults.rs. The settings tabs already receive the resolved config as a prop via ConfigContext, so the placeholder values can come from there directly. Could we drop src/config/constants.ts and use that existing source of truth instead?

[andrewholzbach]

We could, for example it would just look like placeholder={config.inference.ollama_url} in src/settings/tabs/ModelTab.tsx. I figured there might be a reason to have the placeholders strings configured in a different place than the actual resolved url values coming from tauri but otherwise there isn't a point in having src/config/constants.ts. Lmk and I can fix for using defaults.rs instead if preferred

[quiet-node]

I would prefer to place it in src-tauri/src/config/defaults.rs to avoid duplicated code and maintain a single source of truth for the configs. This makes maintenance easier and helps keep things consistent.

[quiet-node]

Also kindly update the PR title to match conventional git commit guidelines as we use the Google release-please workflow to automate releases based on the commit message. This fits as a chore: commit.

[quiet-node]

Perfect LGTM thanks much again for the effort!