Make environmental feeds band-agnostic; add Environment page

- Remove band_assessment and band_detail from SWPC adapter
- Remove all frequency-specific conclusions (906 MHz, 10m-20m, etc.)
- Store only raw indices: SFI, Kp, R/S/G scales, dM/dz gradients
- Let LLM interpret propagation data based on user's band of interest
- Add full Environment page with feed status, solar indices, and ducting data
- Update Dashboard RF Propagation card to show raw values only
- Update alert messages to be frequency-agnostic

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

dashboard-frontend/src/lib/api.ts

@@ -127,8 +127,6 @@ export interface SWPCStatus {
   r_scale?: number
   s_scale?: number
   g_scale?: number
-  band_assessment?: string
-  band_detail?: string
   active_warnings?: string[]
 }
 
@@ -138,7 +136,6 @@ export interface DuctingStatus {
   min_gradient?: number
   duct_thickness_m?: number | null
   duct_base_m?: number | null
-  assessment?: string
   last_update?: string
 }
 
@@ -149,15 +146,12 @@ export interface RFPropagation {
     r_scale?: number
     s_scale?: number
     g_scale?: number
-    band_assessment?: string
-    band_detail?: string
     active_warnings?: string[]
   }
   uhf_ducting: {
     condition?: string
     min_gradient?: number
     duct_thickness_m?: number | null
-    assessment?: string
   }
 }