feat: implement Figlet, Pastel, and Unit tools with a unified layout

- Add Figlet text converter with font selection and history
- Add Pastel color palette generator and manipulation suite
- Add comprehensive Units converter with category-based logic
- Introduce AppShell with Sidebar and Header for navigation
- Modernize theme system with CSS variables and new animations
- Update project configuration and dependencies

public/fonts/figlet-fonts/upper.flc

@@ -0,0 +1,193 @@
+flc2a
+# Upper by Glenn Chappell <ggc@uiuc.edu> 1/94
+# Converts lower-case to upper-case.
+# Modified to support all of Unicode by John Cowan <cowan@ccil.org> 10/96
+# figlet release 2.2 -- November 1996
+#
+# This is a figlet controlfile.
+#
+# Explanation of first line:
+#   flc2 - "magic number" for file identification
+#   a    - should always be `a', for now
+#
+# File body:
+#   The first character of any line is the "command" for that line.
+#   Possible figlet 2.1 commands are as follows:
+#   `#' - comment, continues until end-of-line
+#   `t' - translate, a not-so-fancy version of the Unix "tr" command
+#   `f' - freeze, treat further lines as if they were in a new file
+#
+# The following lines convert lower-case to upper-case.
+#
+# Standard letters:
+t a-z A-Z
+#
+# figlet Deutsch characters (obsolete in 2.2 and later):
+t \-252-\-250 \-255-\-253
+#
+# ISO Latin-1 accented letters:
+t \224-\246 \192-\214
+t \248-\254 \216-\222
+# Note: Latin-1 has no upper-case Y umlaut, so map to "Y".
+# But remove the following line for Unicode fonts.
+t \255 Y
+# This is the proper Unicode mapping, and does no harm for non-Unicode fonts.
+t \255 \0x0178
+# Latin Extended A (Latin-2,3,4,5) accented letters:
+t \0x01\0x01 \0x0100
+t \0x0103 \0x0102
+t \0x0105 \0x0104
+t \0x0107 \0x0106
+t \0x0109 \0x0108
+t \0x010B \0x010A
+t \0x010D \0x010C
+t \0x010F \0x010E
+t \0x01\0x01 \0x0100
+t \0x0103 \0x0102
+t \0x0105 \0x0104
+t \0x0117 \0x0116
+t \0x0119 \0x0118
+t \0x011B \0x011A
+t \0x011D \0x011C
+t \0x011F \0x011E
+t \0x01\0x01 \0x0100
+t \0x0103 \0x0102
+t \0x0105 \0x0104
+t \0x0127 \0x0126
+t \0x0129 \0x0128
+t \0x012B \0x012A
+t \0x012D \0x012C
+t \0x012F \0x012E
+t \0x0131 I
+t \0x0133 \0x0132
+t \0x0135 \0x0134
+t \0x0137 \0x0136
+t \0x0138 K
+t \0x013A \0x0139
+t \0x013C \0x013B
+t \0x013E \0x013D
+t \0x0140 \0x013F
+t \0x0142 \0x0141
+t \0x0144 \0x0143
+t \0x0146 \0x0145
+t \0x0148 \0x0147
+t \0x0149 N
+t \0x014B \0x014A
+t \0x014D \0x014C
+t \0x014F \0x014E
+t \0x0151 \0x0150
+t \0x0153 \0x0152
+t \0x0155 \0x0154
+t \0x0157 \0x0156
+t \0x0159 \0x0158
+t \0x015B \0x015A
+t \0x015D \0x015C
+t \0x015F \0x015E
+t \0x0161 \0x0160
+t \0x0163 \0x0162
+t \0x0165 \0x0164
+t \0x0167 \0x0166
+t \0x0169 \0x0168
+t \0x016B \0x016A
+t \0x016D \0x016C
+t \0x016F \0x016E
+t \0x0171 \0x0170
+t \0x0173 \0x0172
+t \0x0175 \0x0174
+t \0x0177 \0x0176
+t \0x017A \0x0179
+t \0x017C \0x017B
+t \0x017E \0x017D
+t \0x017F S
+# Greek letters:
+\0x037A \0x0399
+\0x0390 \0x0399
+\0x03AC \0x0386
+\0x03AD \0x0388
+\0x03AE \0x0389
+\0x03AF \0x038A
+\0x03B0 \0x03AB
+\0x03B1-\0x03C1 \0x0391-\0x03A1
+\0x03C2 \0x03A3
+\0x03C3-\0x03CB \0x03A3-\0x03AB
+\0x03CC \0x038C
+\0x03CD \0x038E
+\0x03CE \0x038F
+\0x03E3 \0x03E2
+\0x03E5 \0x03E4
+\0x03E7 \0x03E6
+\0x03E9 \0x03E8
+\0x03EB \0x03EA
+\0x03ED \0x03EC
+\0x03EF \0x03ED
+# Cyrillic letters:
+\0x0430-\0x044F \0x0410-\0x042F
+\0x0451-\0x045F \0x0401-\0x040F
+\0x0461 \0x0460
+\0x0463 \0x0461
+\0x0465 \0x0464
+\0x0467 \0x0466
+\0x0469 \0x0468
+\0x046B \0x046A
+\0x046D \0x046C
+\0x046F \0x046E
+\0x0471 \0x0470
+\0x0473 \0x0471
+\0x0475 \0x0474
+\0x0477 \0x0476
+\0x0479 \0x0478
+\0x047B \0x047A
+\0x047D \0x047C
+\0x047F \0x047E
+\0x0481 \0x0480
+\0x0491 \0x0490
+\0x0493 \0x0491
+\0x0495 \0x0494
+\0x0497 \0x0496
+\0x0499 \0x0498
+\0x049B \0x049A
+\0x049D \0x049C
+\0x049F \0x049E
+\0x04A1 \0x04A0
+\0x04A3 \0x04A1
+\0x04A5 \0x04A4
+\0x04A7 \0x04A6
+\0x04A9 \0x04A8
+\0x04AB \0x04AA
+\0x04AD \0x04AC
+\0x04AF \0x04AE
+\0x04B1 \0x04B0
+\0x04B3 \0x04B1
+\0x04B5 \0x04B4
+\0x04B7 \0x04B6
+\0x04B9 \0x04B8
+\0x04BB \0x04BA
+\0x04BD \0x04BC
+\0x04BF \0x04BE
+\0x04C2 \0x04C1
+\0x04C4 \0x04C3
+\0x04C8 \0x04C7
+\0x04CC \0x04CB
+\0x04D1 \0x04D0
+\0x04D3 \0x04D2
+\0x04D5 \0x04D4
+\0x04D7 \0x04D6
+\0x04D9 \0x04D8
+\0x04DB \0x04DA
+\0x04DD \0x04DC
+\0x04DF \0x04DE
+\0x04E1 \0x04E0
+\0x04E3 \0x04E2
+\0x04E5 \0x04E4
+\0x04E7 \0x04E6
+\0x04E9 \0x04E8
+\0x04EB \0x04EA
+\0x04ED \0x04EC
+\0x04EF \0x04EE
+\0x04F1 \0x04F0
+\0x04F3 \0x04F2
+\0x04F5 \0x04F4
+\0x04F7 \0x04F6
+\0x04F9 \0x04F8
+# Armenian letters:
+\0x0561-\0x0586 \0x0531-\0x0556