Play Framework

chore: drop NetBeans + Eclipse IDE support, keep IntelliJ IDEA only

Removes the play eclipsify and play netbeansify CLI commands and
everything that supported them. IntelliJ IDEA stays as the only
first-class IDE (play idealize); other IDEs can still be used via
the manual classpath setup documented in ide.textile's "Custom
configuration" section.

Removed:
- resources/_nbproject/, resources/eclipse/ — IDE project skeletons
  the CLI commands copied from
- framework/pym/play/commands/eclipse.py, netbeans.py — the CLI
  command implementations (commands are auto-discovered from this
  directory; deleting the file unregisters the command)
- documentation/commands/cmd-eclipsify.txt, cmd-netbeansify.txt —
  help.py loads these on demand; play help eclipsify will now
  correctly say "command not found"
- documentation/images/eclipse.png, netbeans.png — only referenced
  from ide.textile, now orphaned. eclipse-plugin/tests/test-runner
  images are kept because they're referenced from historical
  release notes.

Edited:
- documentation/manual{,_ja}/ide.textile — strip Eclipse and NetBeans
  sections; trim intro line to mention only IntelliJ IDEA
- documentation/manual{,_ja}/guide1.textile — drop Eclipse-specific
  VCS-exclusion advice
- documentation/manual{,_ja}/guide7.textile — replace eclipsify advice
  with idealize equivalent
- documentation/cheatsheets{,_ja}/commandLine/... — drop eclipsify
  and netbeansify command entries
- support/play_completion, support/zsh/_play — drop eclipsify/ec and
  netbeansify/nb from bash + zsh completion

Kept (intentional):
- modulesrepo.py:403 filter for /eclipse/ and /nbproject paths is
  defensive packaging logic — users may still hand-create IDE
  projects, and this prevents those artifacts from polluting module
  zips. Independent of whether play itself can generate them.
- openspec/changes/archive/2026-02-15-python-312-compat/ artifacts
  reference these files but archives shouldn't be retroactively
  edited.
- documentation/manual{,_ja}/releases/.../*.textile historical
  release notes still reference the removed commands; they document
  what shipped at the time.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>