v1.2.0: Release 1.2.0 — Enhanced Evidence Gallery (rename) + document support

Rename display name only (Enhanced Image Gallery -> Enhanced Evidence Gallery);
Java package and OpenIDE module code-name unchanged so module identity/upgrades
are preserved. Spec version 1.1.0 -> 1.2.0.

Document support:
- MediaType.DOCUMENT + document MIME/ext sets mirroring AI Text Triage
- on-demand document loading (lazy, only when the Documents filter is enabled)
- document placeholder tiles (icon + extension, TXT fallback), Documents filter
  (default off), external open works for documents
- sidebar groups now respect the active type filter

AI search:
- explicit index radio in the dialog: Images (CLIP) vs Text + OCR (BGE-M3)
- AiTextSearchService client (port 8757), snippets in tile tooltip + PropertiesPanel
- "Find similar" routed by the clicked file's type (document -> BGE-M3)
- recent-search autocomplete (last 5), Enter submits, remembered mode
- result limit raised to 50k + "All" option; "N hidden by filters" counter

Other:
- SVG rendered as a graphic even when typed text/xml; Batik sanitises width/height="auto"
- export selected files to disk (objId_name, collision-safe)
- separate AI tag group (AI:/ClipAI:/TxtAI: prefixes) with precedence
- SPISCOM logo (Java2D) in the top bar and About

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>