refactor(cli): remove redundant doc comments from command files

Removed duplicate help text from doc comments:
- log.zig: Removed usage examples (in printUsage)
- annotate.zig: Removed usage examples (in printUsage)
- experiment.zig: Removed usage examples (in printUsage)

Rationale: printUsage() already contains detailed help text.
Doc comments should not duplicate this information.

All tests pass.

cli/src/commands/annotate.zig

@@ -4,12 +4,6 @@ const db = @import("../db.zig");
 const core = @import("../core.zig");
 const manifest_lib = @import("../manifest.zig");
 
-/// Annotate command - unified metadata annotation
-/// Usage:
-///   ml annotate <run_id> --text "Try lr=3e-4 next"
-///   ml annotate <run_id> --hypothesis "LR scaling helps"
-///   ml annotate <run_id> --outcome validates --confidence 0.9
-///   ml annotate <run_id> --privacy private
 pub fn execute(allocator: std.mem.Allocator, args: []const []const u8) !void {
     var flags = core.flags.CommonFlags{};
     var command_args = try core.flags.parseCommon(allocator, args, &flags);

cli/src/commands/experiment.zig

@@ -24,11 +24,6 @@ const ExperimentInfo = struct {
     }
 };
 
-/// Experiment command - manage experiments
-/// Usage:
-///   ml experiment create --name "baseline-cnn"
-///   ml experiment list
-///   ml experiment show <experiment_id>
 pub fn execute(allocator: std.mem.Allocator, args: []const []const u8) !void {
     var flags = core.flags.CommonFlags{};
     var command_args = try core.flags.parseCommon(allocator, args, &flags);

cli/src/commands/log.zig

@@ -7,10 +7,6 @@ const ws = @import("../net/ws/client.zig");
 const protocol = @import("../net/protocol.zig");
 const crypto = @import("../utils/crypto.zig");
 
-/// Logs command - fetch or stream run logs
-/// Usage:
-///   ml logs <run_id>              # Fetch logs from local file or server
-///   ml logs <run_id> --follow     # Stream logs from server
 pub fn run(allocator: std.mem.Allocator, args: []const []const u8) !void {
     var flags: core.flags.CommonFlags = .{};