Fix: RangeError 'Invalid time value' in Safari date parsing

[sentry]

This PR addresses the RangeError: Invalid time value occurring specifically on iPhone/Mobile Safari when displaying job available_from/available_to dates.

Root Cause:
Safari's JavaScript engine cannot parse date strings containing dashes (e.g., '2024-01-01'), resulting in an Invalid Date object. The dateTimeFormat() function in src/utils/common.ts was directly passing these raw, dash-separated strings to date-fns's format() function. When format() receives an Invalid Date, it throws the observed RangeError.

Solution:

1. Modified dateTimeFormat() to utilize the existing toDate() helper function (also in src/utils/common.ts). toDate() correctly converts dash-separated date strings to slash-separated ones (e.g., '2024/01/01'), which Safari can parse.
2. Added a guard using date-fns's isValid() function. If, after conversion, the date is still invalid, dateTimeFormat() will now return an empty string, preventing the RangeError from being thrown and ensuring a graceful fallback.

Fixes SH-STUDENT-APP-W
Fixes TECH-2019

[linear-code]

TECH-2019

[netlify]

✅ Deploy Preview for studenthub-student ready!

Name	Link
🔨 Latest commit	ff4b792
🔍 Latest deploy log	https://app.netlify.com/projects/studenthub-student/deploys/6a4d25ce4457ef00097bfb42
😎 Deploy Preview	https://deploy-preview-36--studenthub-student.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[sentry]

Bug: The toDate() function's global dash replacement corrupts ISO 8601 timestamps, causing new Date() to fail and downstream date formatting to return an empty string.
_{Severity: HIGH}

Suggested Fix

Modify toDate() to avoid corrupting ISO 8601 timestamps. Instead of a global replacement, consider splitting the string by 'T', replacing dashes only in the date part, and then rejoining. Alternatively, use a more robust date parsing library or method that correctly handles ISO strings without manual manipulation.

Prompt for AI Agent

Review the code at the location below. A potential bug has been identified by an AI
agent. Verify if this is a real issue. If it is, propose a fix; if not, explain why it's
not valid.

Location: src/utils/common.ts#L6

Potential issue: The `toDate()` function globally replaces all dashes with slashes. When
called with an ISO 8601 string containing a 'T' separator (e.g., from
`Date.toISOString()`), it produces an invalid date format like
"2024/01/01T09:30:00.000Z". This string cannot be parsed by `new Date()`, leading to an
`Invalid Date` object. Consequently, `dateTimeFormat()` returns an empty string, causing
UI components like date pickers in `form-datetime.tsx` and `date-dropdown.tsx` to
display blank values.

Also affects:

• form-datetime.tsx:59
• date-dropdown.tsx:35

_{Did we get this right? 👍 / 👎 to inform future reviews.}