Add Space Missile SIDC support (06)

[TomQuez]

User Story

As a developer integrating STANAG APP-6D symbology into a C2 application,
I want the library to support Symbol Set 06 (Space Missile),
so that SIDCs referencing space-based missile entities can be properly decoded.

Acceptance Criteria

• Three TSV data files exist in tsv-tables/app6d/: Space missile.tsv, Space missile sector 1.tsv, Space missile sector 2.tsv, populated with
  entity and modifier codes per the APP-6D / MIL-STD-2525D standard
• src/app6d.js imports the three Space Missile TSV files and exports a "06" entry with mainIcon, modifier1, and modifier2 fields
• The built bundles (stanagapp6.js, stanagapp6.esm.js) include the "06" symbol set after npm run build
• A lookup using a SIDC with symbol set 06 returns the expected entity name and modifier descriptions

Out of scope

• APP-6B support for space missiles (APP-6B uses a different coding scheme and is not structured by symbol set)

Technical notes

• Symbol Set 06 (Space Missile) follows the same pattern as Symbol Set 02 (Air Missile): a main icon table for missile entities, and two modifier
  tables (sector 1 / sector 2)
• The existing Air Missile implementation ("02" in src/app6d.js) serves as a direct structural template
• Codes should match the official APP-6D / MIL-STD-2525D tables
• The tsv2json() helper already handles the TSV format; no parser changes are needed
• Insert the "06" block between the "05" (Space) and "10" (Land Unit) entries in src/app6d.js to maintain ordering consistency

[TomQuez]

Currently working on this on a fork. PR soon to be 😅

[spatialillusions]

Think the easiest thing is to just modify the APP6 E tables.

https://github.com/spatialillusions/milstandard-e