Add page-level share button with referral ID

[Copilot]

Section anchor links already append ?rid=<referralId> when copied, but there was no way to share the page URL itself with a referral ID attached.

Changes

• useSiteShell.js

  • Extracted addReferralIdToUrl(url) helper — eliminates duplicated referral ID injection logic
  • Extracted writeToClipboard(url, successMessage?) helper — shared by both copy functions
  • Added shareCurrentPage() — copies current page URL (no hash) with referral ID as ?rid=... if available; exposed in composable return

• PageNavigation.vue

  • Added a centered fa-solid fa-share-from-square button between prev/next arrows
  • Rendered only on content pages (v-if="shell.isContentPage")
  • Calls shareCurrentPage() on click with a "Share Page" tooltip

• styles.css

  • Added .tooltip-center for the share button tooltip positioning
  • Added border/padding reset for <button>.arrow-btn to match <a> sibling appearance

[Copilot]

Pull request overview

Adds a page-level “Share” action to copy the current page URL (without hash) with the referral ID (rid) appended when available, aligning page sharing behavior with existing section-link sharing.

Changes:

• Refactors clipboard/referral URL handling into shared helpers and introduces shareCurrentPage() in useSiteShell.js.
• Adds a centered share button to the page navigation UI (content pages only).
• Updates CSS to support centered tooltip positioning and button styling parity with existing nav arrows.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
EssentialCSharp.Web/wwwroot/css/styles.css	Adds centered tooltip positioning and button reset styles for the new share control.
EssentialCSharp.Web/src/composables/useSiteShell.js	Extracts referral/clipboard helpers and adds shareCurrentPage() to copy the page URL with rid.
EssentialCSharp.Web/src/components/PageNavigation.vue	Introduces a share button between prev/next navigation arrows and wires it to shareCurrentPage().

Comments suppressed due to low confidence (1)

EssentialCSharp.Web/src/composables/useSiteShell.js:112

• The error snackbar message uses string interpolation on the raw error object, which often renders as [object DOMException] and isn’t helpful to users. Consider surfacing a friendlier message (e.g., error.message when available) while keeping the detailed object in console.error.

                (error) => {
                    console.error("Could not copy text to clipboard: ", error);
                    snackbarColor.value = "red";
                    snackbarMessage.value = `Error: Could not copy text to clipboard: ${error}`;
                }

[BenjaminMichaelis]

@copilot There is some feedback on #1050

[Copilot]

@copilot There is some feedback on #1050

Both review comments addressed in a42a4eb:

1. writeToClipboard timeout ordering — the clearTimeout/setTimeout calls are now inside the .then() success and error handlers, so the timeout only starts after snackbarMessage has been set (no risk of it firing before the clipboard promise resolves).

2. type="button" on share button — added to prevent accidental form submission.