Improve severity labels in Actions logs and tweak colors (#36993)

Add support for error, warning, notice, and debug log commands with bold
label prefixes and colored backgrounds matching GitHub's style. Parse
both `##[cmd]` and `::cmd args::` formats.

Also improved the severity colors globally and added a devtest page for
these.

---------

Co-authored-by: Claude (claude-opus-4-6) <noreply@anthropic.com>

web_src/css/base.css

@@ -393,12 +393,6 @@ img.ui.avatar,
   aspect-ratio: 1;
 }
 
-.ui.error.message .header,
-.ui.warning.message .header {
-  color: inherit;
-  filter: saturate(2);
-}
-
 .full.height {
   flex-grow: 1;
   padding-bottom: var(--page-space-bottom);

web_src/css/modules/message.css

@@ -41,9 +41,9 @@
   margin-bottom: 1em;
 }
 
-.ui.info.message .header,
-.ui.blue.message .header {
-  color: var(--color-blue);
+.ui.message .header {
+  color: inherit;
+  filter: saturate(2);
 }
 
 .ui.info.message,
@@ -55,12 +55,6 @@
   border-color: var(--color-info-border);
 }
 
-.ui.success.message .header,
-.ui.positive.message .header,
-.ui.green.message .header {
-  color: var(--color-green);
-}
-
 .ui.success.message,
 .ui.attached.success.message,
 .ui.positive.message,
@@ -70,12 +64,6 @@
   border-color: var(--color-success-border);
 }
 
-.ui.error.message .header,
-.ui.negative.message .header,
-.ui.red.message .header {
-  color: var(--color-red);
-}
-
 .ui.error.message,
 .ui.attached.error.message,
 .ui.red.message,
@@ -87,11 +75,6 @@
   border-color: var(--color-error-border);
 }
 
-.ui.warning.message .header,
-.ui.yellow.message .header {
-  color: var(--color-yellow);
-}
-
 .ui.warning.message,
 .ui.attached.warning.message,
 .ui.yellow.message,

web_src/css/themes/theme-gitea-dark.css

@@ -162,20 +162,20 @@ gitea-theme-meta-info {
   --color-diff-removed-row-border: #634343;
   --color-diff-removed-word-bg: #6f3333;
   --color-diff-inactive: #22282d;
-  --color-error-border: #a04141;
-  --color-error-bg: #522;
-  --color-error-bg-active: #744;
-  --color-error-bg-hover: #633;
-  --color-error-text: #f9cbcb;
+  --color-error-border: #da3633;
+  --color-error-bg: #3c2425;
+  --color-error-bg-active: #5a3637;
+  --color-error-bg-hover: #4c2d2e;
+  --color-error-text: #f5817c;
   --color-success-border: #458a57;
   --color-success-bg: #284034;
-  --color-success-text: #6cc664;
-  --color-warning-border: #bb9d00;
-  --color-warning-bg: #3a3a30;
-  --color-warning-text: #fbbd08;
+  --color-success-text: #69be61;
+  --color-warning-border: #9e6a03;
+  --color-warning-bg: #2f2a1b;
+  --color-warning-text: #d29922;
   --color-info-border: #306090;
   --color-info-bg: #26354c;
-  --color-info-text: #38a8e8;
+  --color-info-text: #48b7f8;
   --color-red-badge: #db2828;
   --color-red-badge-bg: #db28281a;
   --color-red-badge-hover-bg: #db28284d;

web_src/css/themes/theme-gitea-light.css

@@ -162,20 +162,20 @@ gitea-theme-meta-info {
   --color-diff-removed-row-border: #f1c0c0;
   --color-diff-removed-word-bg: #fdb8c0;
   --color-diff-inactive: #f0f2f4;
-  --color-error-border: #e0b4b4;
-  --color-error-bg: #fff6f6;
-  --color-error-bg-active: #fbb;
-  --color-error-bg-hover: #fdd;
-  --color-error-text: #9f3a38;
-  --color-success-border: #a3c293;
-  --color-success-bg: #fcfff5;
-  --color-success-text: #2c662d;
-  --color-warning-border: #c9ba9b;
-  --color-warning-bg: #fffaf3;
-  --color-warning-text: #573a08;
-  --color-info-border: #a9d5de;
-  --color-info-bg: #f8ffff;
-  --color-info-text: #276f86;
+  --color-error-border: #d63333;
+  --color-error-bg: #ffebeb;
+  --color-error-bg-active: #fdd;
+  --color-error-bg-hover: #fee;
+  --color-error-text: #8a3231;
+  --color-success-border: #49842b;
+  --color-success-bg: #eef6e4;
+  --color-success-text: #2f6e30;
+  --color-warning-border: #bf8700;
+  --color-warning-bg: #fff8e1;
+  --color-warning-text: #744500;
+  --color-info-border: #2d8fa8;
+  --color-info-bg: #e8f4fd;
+  --color-info-text: #216078;
   --color-red-badge: #db2828;
   --color-red-badge-bg: #db28281a;
   --color-red-badge-hover-bg: #db28284d;