feat: add archiving of platform media files (#1)

* chore: specify non-ignored `.md` files

* refactor: rename youtube downloader to ytdlp

More generic name since yt-dlp supports many sites beyond YouTube.

* feat: add local file downloader

Supports file:// URLs for archiving local files.

* deps: add regex crate for URL pattern matching

* feat: expand source detection with granular YouTube types

- Split Source::YouTube into YouTubeVideo, YouTubePlaylist, YouTubeChannel
- Add Source::X for Twitter/X posts
- Add Source::Local for file:// URLs
- Add regex-based URL pattern matching for YouTube URLs
- Add shorthand schemes (yt:video/ID, youtube:playlist/ID, etc.)
- Add comprehensive tests for all URL patterns

* docs: update README milestones

Mark YouTube videos, Twitter videos, and local files as done.

* chore: update flake.lock

* feat: add shorthand schemes for X/Twitter media

* chore: move docs into docs dir

* Remove temp file using timestamp path

Delete the temp entry at store_path/temp/<timestamp> in both
the hash-exists and success paths. Stop constructing the full filename
with extension and remove the early process::exit to de-duplicate
cleanup.

* Add Nix caches and default flake package

* Add social platform source detection and update milestones

* Tighten social URL matching to avoid false positives

* Mark media archiving milestone complete

Cargo.lock

@@ -2,6 +2,15 @@
 # It is not intended for manual editing.
 version = 4
 
+[[package]]
+name = "aho-corasick"
+version = "1.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ddd31a130427c27518df266943a5308ed92d4b226cc639f5a8f1002816174301"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "android_system_properties"
 version = "0.1.5"
@@ -75,6 +84,7 @@ dependencies = [
  "chrono",
  "clap",
  "hex",
+ "regex",
  "sha3",
  "uuid",
 ]
@@ -311,6 +321,12 @@ version = "0.4.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "34080505efa8e45a4b816c349525ebe327ceaa8559756f0356cba97ef3bf7432"
 
+[[package]]
+name = "memchr"
+version = "2.7.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f52b00d39961fc5b2736ea853c9cc86238e165017a493d1d5c8eac6bdc4cc273"
+
 [[package]]
 name = "num-traits"
 version = "0.2.19"
@@ -356,6 +372,35 @@ version = "5.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "69cdb34c158ceb288df11e18b4bd39de994f6657d83847bdffdbd7f346754b0f"
 
+[[package]]
+name = "regex"
+version = "1.12.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "843bc0191f75f3e22651ae5f1e72939ab2f72a4bc30fa80a066bd66edefc24d4"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-automata",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-automata"
+version = "0.4.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5276caf25ac86c8d810222b3dbb938e512c55c6831a10f3e6ed1c93b84041f1c"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.8.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7a2d987857b319362043e95f5353c0535c1f58eec5336fdfcf626430af7def58"
+
 [[package]]
 name = "rustversion"
 version = "1.0.22"