Use actual date of last fire update to report current fire count/tally

[brucecrevensten]

Testing:

• Run the app. Note that the date shown in the highlighted blurb now uses the date in the status.json file.
• Comment out line 312 in App.vue to simulate failure to load the status.json file. Observe that the highlighted fire count/tally blurb is not shown / there is no console error.
• Code note: this PR also flushes out some old stuff in the default env file.