Restore what the #121 follow-ups had fixed

[jolavillette]

Items 4–10 of my review on RetroShare#129: the things the RetroShare#121 follow-ups had fixed, each restored with master as the reference.

• All section back for channels, boards and forums (all_*.js), fed by the full list sorted by popularity. Popular and Other are the two halves of the non-subscribed list, so the section labelled "All Channels" hid every subscribed channel and the five most popular; Other is labelled Other again. /channels/All, /boards/All, /forums/All (the phone default tab on master, so in bookmarks) resolve again instead of rendering m(undefined). Forums have no popularity split, so their empty "Other" page is gone.
• [hidden] { display: none !important } in the base sheet. The UA sheet hides the attribute, but an author display rule on the same element wins regardless of specificity, and the channel post placeholder sets display: flex on itself: the "No image" box showed under every real thumbnail (defnax's screenshot). The image error fallback now clears the attribute instead of writing an inline display.
• Distant chat: removing an attached picture clears the session's copy too, or selectChatContact restores it and it goes out with the next message after a contact switch.
• Ctrl/Cmd+Enter inserts a newline again in the shared composer (execCommand first, keeps the undo stack, splice fallback), and the field carries enterkeyhint=send again.
• In-channel post search rendered at every width: the page head, which hosts the channels search, is not rendered inside a channel, so a desktop had no post search.
• Forum thread search shows on phones again: the ≤700px block had lost its display: flex.
• List filters for channels and forums live in module state, like the isSearched flags they set: the field is unmounted inside a group and recreated on the way back, and came back empty while every non-matching group stayed hidden. Clearing resets the flags instead of calling the per-forum loader with no id (which POSTed getForumsInfo with forumIds: [null]); a group reloaded under an active filter is filtered too. The channels and posts fields gain a clear button.
• Modal close buttons get the 44px touch box under the touch mixin; the 26px pointer target is what master's phone padding rule used to correct.

Checked: sass reproduces styles.css, eslint clean, build.js --check passes. Not exercised in a browser here.

Prepared with AI assistance (Claude), driven and reviewed by me.

🤖 Generated with Claude Code